This is an important point. Looking at open job reqs can give the impression that X is very successful, when the reality is that any organization using X has a

This is an important point. Looking at open job reqs can give the impression that X is very successful, when the reality is that any organization using X has an explosion in how many developers they need, and also a high burnout rate in the ones they have. Plenty of other developers quietly and more-or-less-happily working with non-X, and you never see their job in the job boards.