Ask HN: Quiting Big Tech, what is it like?

Ask HN: Quiting Big Tech, what is it like?
I've spent the last decade in two FANG companies, and I've got to a high level where my total compensation is ridiculous. The problem is that it bores me to tears, and I don't want to do it anymore. At first thought, maybe I am burned out? However, I can still come home and write code for a side-project, so I don't think this is "burn-out". I don't know to be honest. I think the best description is that I am cynical of the "mission", and I can't connect my work to people I care about. How do I know what the source of the problem is? However, I wanted to pose two questions. First, what is the environment like for exiting high-level former-FANG employees? Second, what are some of the surprises post-FANG that I would be in for if I wanted to start a company? Thank you for your time.