I've long suspected the "10x developer" is mostly (but perhaps not entirely!) a result of above-average ability to spot the right teams and projects for one to

I've long suspected the "10x developer" is mostly (but perhaps not entirely!) a result of above-average ability to spot the right teams and projects for one to be successful, and/or some early luck, followed by compounding success because before long they have the reputation to get on the right kinds of teams doing the right kinds of (high-impact, enjoyable) projects that let them work their best and do things that are highly visible to important people in the company hierarchy. I think this is why famous developers tend to either stick with a place a long time, or bail really fast—in the latter case, because they realize they made a mistake and won't be as productive as usual, because the organization as it relates to them (key point: they may get special treatment many places, so their experience may not be everyone's) sucks. Lots of workers tough it out if it's not too bad, while people accustomed to being "10x" run the hell away if the management + team + project combo isn't just right for them. I bet my personal productivity has varied by at least 10x the lowest level, depending on where I'm working and what I'm working on, even adjusted for experience level and such, entirely due to work environment and the kinds of projects I'm on. Though perhaps that lowest-level was "0.1x" or whatever, I dunno.