".. However, StackOverflow’s survey on age shows that there are just about 13% of developers after 40. Where are the others?" Obviously not on StackOverflow. Perhaps they have enough experience and knowledge to not need the site because they either know how to read tech books and sites to get the info they need when they have a problem using pre-existing docs, or conversely, are fully able to debug issues themselves.…
The other problem is I removed my training wheels in the 80s or 90s, and my problems are almost purely subjective, like "what is the best virtualization system running on FreeBSD" Google search of stackoverflow finds no question asked. Thanks stackoverflow you're really helpful when I forget what command copies files on linux (kidding), but not for the important stuff.
The next problem is seen at this URL
https://stackoverflow.com/questions/14966014/whats-the-best-...
OK thanks stackoverflow for having the same question but for linux perhaps I can work off that ... wait, whats that, "asked 4 years, 2 months ago" Well I can't work with data that old, may as well not even be on line... And whats this... "As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance." Well, stackoverflow can just go F itself. It certainly doesn't answer any question I need answered.
My examples above were pretty staged, but across real topics, SO does boil down to a medium-to-slow speed way of answering relatively low level questions. Old timers work too quick, and they've already learned too much to ask the kind of question SO can answer.