LOL but but but but ... *why* did you binge on self-help books in 2020?! I *know* you knew the jig was up by then. :)
Sadly, I think while self-help in a vacuum is dead, there will always be a desire--maybe now more than before, given how awful we're (to varying degrees) getting it from the powers that be--to dream of being someone else: someone who seems like they have their shit together, someone who has what we want, someone who's in better shape than we are, someone who's in cinematic love, someone who doesn't have to work so fucking hard to survive anymore.
Those people: the pretty ones, the rich ones, the adventurous ones, the trendy ones, the in-love ones, the in-control ones, the spiritually embodied ones, the powerful ones ... they will always be models for *somebody.*
Their content might be steaming tone-deaf garbage and it 98% of the time is, but if they can just do the bare minimum: pull-quote Seneca, or regurgitate a parable in the form of "I was in the backseat of an Uber with a wealthy businessman who was less happy than the driver...", and call their screen-filler "writing"--then they're not selling you on what they say. No, the pretty, rich, adventurous, trendy, in love, in control, spiritually embodied, and powerful ... the idea of being any of those things (in an era when so few of us *can* be) is what you bought.
The self-help writing's just the post-sale retargeted advertising. So when it's time for those people to monetize you again, you--being no better off in life but still hoping to be them someday--will be ready to re-up again.