Sure. I didn't deny that Chris has always had some form of main character syndrome. But there is certainly a huge difference with what he had in 2009 compared to the God complex he has today. There is a difference between wishing you were a God vs actually believing it and as ToroidalBoat said
I believe Chris has advanced these delusions mostly in part by how shitty has life as gotten. As in, the older he gets, the more garbage his life has become, thus he compensates heavily with how he views himself.
Back in the 2000s, you could pretty much just up and talk to Chris, and he'd blab on about whatever. Over the decades, he's learned that interacting like that isn't from genuine fans, but people just trying to get a laugh from him. So that made him extremely distrustful of anyone contacting him (which is another weird thing with Flutter). He was seen as immature, a jerk, and a retard back then, and that has gradually creeped into his head after trying to go after famous people like the Brony analysis folks. He just can't wrap his head around why those people don't want to interact with him. It doesn't help with Caden and Flutter dumping chum buckets of praise on him, telling him how amazing and great he is, but then he turns around and gets treated like a leper.
He probably had some ideas of what he'd be like in his forties, probably have a woman, family, finally recognized for his "talents", but none of that has come. He's famous, but for all the wrong reasons, and he's gradually able to comprehend that he's a dancing monkey, that people only pay attention to for a good laugh. I'd like to think that he understands Caden is running the show, not him, and that has fomented some sort of resentment. Like Chris didn't make all these sales of merch, it was
someone else.
Basically the all mighty Chris of the 2000s, who thought he could do everything, couldn't. Now he needs crutches to get his name out there, and when he highlights how he's change or his new creations, his stupid gospels, no one really gives a fuck. I mean the most interesting thing about the Goddess writings is that Chris is all for incest in any form, even for making a kid. The rest? No one really cares.
So now that he's absorbed all that, mixed in with getting outright banned from public gatherings he felt so welcomed at, he has to compensate by thinking he's even more great than he once was. Once Barb dies and Caden gets bored with him, we'll really see him go off the rails.