Some of the change came from finally paying off debts and having well-funded retirement and savings accounts. I can finally afford to not try to make more money, so suddenly the super stressful job with the mind boggling salary just isn't worth the stress. I recognize there's certainly privilege there, and I would hope that someday we're all so lucky as to have solid safety nets.
The rest of the change came from having a broader view of the impacts (and non-impacts) my work has. I don't like being part of the wealth inequality gap in the US. I don't like working for tech companies that use their mission statement to devalue and underpay their workers. I don't like contributing to technologies that are being used in backroom deals to support burgeoning humanitarian crises (whether that's creating racially biased algorithms, selling personal data, or literally building bombs). So much of Silicon Valley is well-intentioned but myopic engineers building tools that greedy business people sell to the highest bidder without regard to their final use case. And speaking up, regardless of the HR propaganda, doesn't work-- they will quickly show you the door and corner you into silence with lawyers and hush money (which, on the flip side, is one way to fully fund retirement and savings accounts).
So I'm in my mid-30s, still young by non-silicon valley standards, working through a bit of an identity crisis to figure out what goals really are worthwhile. But my 20s taught me that selling my soul to someone else's company isn't my goal. And building my own company with VC money isn't my goal. So I'm left with tending my personal relationships, refocusing my career outside of startups (back to nonprofits and academia), spending more time outdoors, and pursuing whatever tangential curiosity piques my interest this week.