Thanks for sharing your journey. I, too, was an active contributor for many years (not so much on SO but on several of the other sites), and I had to learn the rules and the process and the culture like you did. Individual communities vary, but I had some great experiences.
In recent years the company has taken some (IMO) serious missteps, driving out a bunch of their (former) top contributors. It felt like the company, instead of working with the community in partnership, found the community to be a burden. They lost the community focus they once had, unfortunately.
Some of us decided to try again, putting the community first with an open-source platform and a non-profit organization. We're small but we've been able to build some exciting new tools on the Q&A foundation, and we're building a network of communities that are community-run. We have a Software Development community (https://software.codidact.com/); it doesn't get 6000 questions per day like SO, but it gets questions and they get answers. Perhaps you'll add it to your rounds, popping in occasionally to see what interests you there too? You can learn more about the project at https://codidact.org/.