For the most part I liked the companies I worked at (which tended to be ~50 people when I joined) and my coworkers. The problems were interesting, though largely not things I was especially passionate about (I spent a couple years making software for call centers, a couple years on enterprise videoconferencing, etc.).
I decided to go my own way for a few reasons. First was financial - I had already started investing in some real estate on the side, and it wasn't a leap to see how much of a financial advantage you can gain from owning and running an operating business vs. being a salaried employee. Second was just that I really like to be in control. Even in a 100% self-owned small business you find that you're not really in control on a lot of things (getting permits from the city for stuff is exhausting, plus you've got a landlord, bank, etc.), but from a day-to-day perspective, I am the one who makes the call on everything.
Last was that it was a good way out of SF. I'm engaged (would've been married in three days... sigh), and I just have no desire to have kids anywhere in the Bay Area. This allowed me to move to San Diego, a place that I love and that is also perfect for this business.
Edit: To answer the last couple parts of the question, no regrets (I mean I guess in theory I would've kept working a steady job and started the business post-pandemic, but I believe all my choices were sound at the time that I made them). Also I still follow HN because I'll always be interested in tech.