I can only speak for myself, but her slightly-less-fatness has shit all to do with my disinterest. I'd argue a lot of people are just sick of the boring, repetitive nature of her uploads at this point and are seeking something more interesting and less predictable. After so many cycles of the same click-baity antics, it's not even worth the hate watch at a certain point. Once you really see the game for what it is, what's left to say? Calling her a fat pig? Telling her to get professional help and save herself? It doesn't matter to her. She gets paid either way. If it mattered that much, she'd shut off the comment section and take a long, long hiatus from the internet.
Amber probably still makes enough to be comfortable (one of the benefits of living in Kentucky, where cost of living is already pretty low). But she's also getting older , more prone to illness, and has no backup plan. I think her move to Tic Tok is what she considers a backup plan, except she has too much notoriety on various other platforms now, so there's no way she can ever truly reinvent herself and acquire the respect and fandom that she used to enjoy before the paychecks got bigger and she stopped acting like she gave a singular fuck about her health or what other people think about her health.
Her being slightly less fat has nothing to do with it, IMHO. Because the only weight she's actually lost came from her body fighting infections all winter and a pandemic which has not stopped her weight gain, but slowed it a bit. She's just too limited in what you can do now, and so lacking in creativity, that the best she can offer is more of the same. Not just more of the same, but more of the same from weeks ago. That's the degree of fucking laziness we're dealing with here.