People like Amber (or Steve Assanti, or Boogie2988 ) don't communicate the way normal people do. Like, regular people communicate to exchange ideas/information, or to express their feelings. Generally to accomplish something, or to resolve an issue. Narcissists don't. Communication is a weapon they use. Their goal is to control and dominate situations and people, or to break things down. Because of this, things like "truth" are relative and depend on whatever outcome they're trying to achieve. Same with expressions of emotion. They are weapons; nothing more.
Look at Boogie for example. Over the course of 3 lolcow lives (about 10 hours of constant pressure from Destiny, Mutahar, and a few others), and constant misdirection and tantrums, Boogie FINALLY admitted that he lied about a formal diagnosis of cancer, or that his doctor even mentioned the word cancer to him. This was after over an hour straight of him holding his phone saying "I'm reading it right here on my health portal... but it's private and I won't show you". When finally backed into a corner, he says "It's not on my portal... I TOLD YOU THAT. It's in my chart.." Then it wasn't in the chart, but his doctor knows about it. Then it was that his doctor doesn't speak english well and Boogie couldn't understand him. Then it was that the doctor for the CPAP machine told him that it was for his "cancer". Then it was that the treatment for his blood disorder (which he has no proof for either) was the same for both the cancerous and non-cancerous versions, so that means for all intents and purposes he has cancer. Then it became that his doctor also suspects that he may have, like, 2 other types of cancer (including "ass cancer" - as if a doctor would say to a patient "I'm concerned that you might have ASS CANCER"). And all of that backtracking nonsense occured over 1 or 2 lolcowlive episodes while Boogie was throwing random accusations about the people accusing him of lying, screaming constantly so no one else could get a word in, pounding his fists on the table, and threatening self-harm to the point where he storms out of the room and comes back on camera with a paring knife and threatens to slit his wrists on camera. I wouldn't be surprised if Amber did a lot of these things behind the scenes - of course, sandwiched inbetween backhanded apologies ("I'm sorry BUT you know that when you say *this* it MAKES me do *that*") and love-bombing.
They also have infinite memories and endless energy when it comes to achieving their goals of control. Narcissists are ON every minute of the day, slowly undoing any progress made, or chipping away at boundaries. There is no low that's 'too low' for a narcissist to accomplish their goals. They'll remember every single little insecurity of mistake you make, to weaponize against you later. It doesn't matter if that's a week, month, year, or even DECADE later. Every time you have an issue that needs addressing, they'll bring up 5 'more important' problems they have with you that need addressing. And when you deal with that, they'll have another 10 more. You'll hit a point where you realize that you are working on problem #57 that they had with you, while they haven't addressed even ONE of your concerns. And when forced to deal with it, they may agree to your terms, then do whatever they want afterwards and pretend to have no memory of the conversation. Slight PL, but I experienced this personally. And after several discussions where the person agreed to do something (then never did), they turned around and said "we just keep on going in circles on this topic and never resolve anything, so there's no point in discussing it anymore". The way Amber keeps saying that she's changed in some regard - only to IMMEDIATELY revert back to her old ways within days/weeks, I'm certain this is a tactic she uses.
Then they keep creating problems for you to solve. Stuff they should know how to do (or could do before they met you) suddenly becomes too difficult due to stress/mental issues/whatever. Amber showed an example of this when she boasted about having never used her own bank card herself. That's obviously bullshit, but I could see her making Becky do all of the shopping for her due to her 'mentulz'. During the Wipey era, Amber filmed herself sitting outside of the hospital while Jade was inside booking follow up appointments for Amber. Amber cried about her health (mental and physical), while actively sabotaging it, yet kept using it as a excuse to control the movements of her partners, or to have everything done for her. Remember the excuses she made about being unable to do her own laundry because of her t-rex arms? Her constant "back pain" that kept her from any cleaning? Oh the constant "ang-zite" complaints that required her partners to step in to somehow mitigate it for her? Or even just the "sponge-bath" era (you KNOW Becky had to scrub her down and it wasn't Amber washing herself).
Another element that Amber adds to it is sleep deprivation. She refuses to follow a normal "awake in the day, asleep at night " schedule - and makes her girlfriends follow Amber's schedule. Jade didn't, and Amber responded by binging at night and then writing letters to Jade about it that she made Jade read the next morning. Even if Becky stopped working and could take up Amber's sleep schedule, everyone else in her life were on normal sleep schedules. Becky was trying to deal with her family and Eric/Rickie on day schedules, while Amber pushed her to stay up with her. It's harder to see the stuff mentioned above and deal with it when you're in a zombified state from lack of sleep. It's like having 'new-mommy brain', except in the case of babies, they eventually start sleeping through the night by themselves.
And of course, while all of this is happening, some narcissists also start "smear campaigns" against their victims. This starts with isolating the victim and discouraging them from having contact with their friends, or making excuses why they can't come visit. Then it either escalates into them getting into feuds with them to force the victim to choose the abuser and willingly isolate themself, or the abuser will go behind the victim's back and pretend to be a victim and turn the true victim's friends/family against them. Or even trying to ruin their reputation at work, or with whatever communities they're involved in. Again PL, but I've seen this happen to people I know. It's unreal watching someone who is and has always been a genuinely good person be turned on by blood (and by blood I mean parents turning on adult children, or siblings who were close getting alienated due to the narcissist, etc.), and wondering how they were so quick to trust essentially a stranger. We saw Amber do this by creating the feuds with Rafe and Norma, and she managed to turn Eric and Rickie against Becky (yeah, they're just turds, but still).
And I have a feeling that the logistics of kicking the beast out (of the gaycare) would have been difficult. Even if Becky broke up with Amber and got a job, how would they boot her from that house? She's paying rent, and they don't own the property. They would have to convince the landlord to evict her. And then covid came along that would have made it harder. And while you're waiting for her to get the boot, you have to deal with her screeching, crying, and sabotaging behaviour.... Non-Stop.... Day and night.... while she shoves a camera in your face. And then Amber had surgery, and I'm sure Becky was wondering about the consequences of bailing on Amber when she was completely unable to care for herself after surgery. And I'm sure that when you're a sleep-deprived, off-your-tits from psych drugs (that you probably shouldn't even be on), and are a barely sentient thumb, it can be tough to separate yourself from this.
OR... you know, this was all a grift. But to be honest, I don't know how even the laziest and griftiest person could see all of *this* as better than getting a job as a Walmart greeter so they could ditch the bitch and exist in peace. I'm willing to believe it started as a grift, and laziness played a decent factor in Becky staying for so long, but I think the narcissistic abuse played a large role in keeping her locked in.