People vary yes, but do we have 10x variation in performance? Actually for 10x to be a meaningful size, would need significantly more variation. Can one find support for such level of variation in other, more well studied fields? Say students, managers, factory workers?

Sorry for the downvotes; I upvoted you to correct. I think it's an interesting question. There are probably fields where it's possible and fields where it's not.

Some students certainly outperform others by a factor of ten. I'd hesitate to score managers numerically, but it seems plausible that working for one could feel ten times more smooth or whatever than working for another, whatever that means. Intuitively, probably not factory workers, but prove me wrong.

10x is not actually that much. I could play basketball with Michael Jordan or chess with Magnus Carlsen, and they'd win essentially an infinite number of games against me without losing once. That doesn't mean they're infinitely better, because theoretically I could through practice become as good as them, but the factor is way more than 10.

Re 'factory worker'. When I studied, I worked part-time in a shop selling bicycles. One of my main tasks was assembling & tuning the bicycles (they come flatpacked). I recall that on my first day (as a 14 year old with no prior experience), I could only complete one bike, with another one in progress. The teaching was mostly 'here are the tools, tell us when done/stuck'. A couple years, maybe 1000 hours of experience later, I would average around 3 bikes per hour. So, a factor 12-15 speedup. This was basically as fast as the guys who had been doing it 20-30 years full-time. I stayed basically at that level until I stopped at 6 years. Note, this was no sweatshop, just a pretty active and successful self-owned store.

It is possible that those that assemble Ikea furniture for a living have 10x over a typical Ikea-buyer.

I can also do programming things in 1x which friends who fiddle with Arduinos can't do in 10x the time. But they are non-professionals, and may even stuggle with fizzbuzz.

But in a professional setting I've yet to meet a single developer I would claim to 10x. Probably not even 5x. Unless one would look isolated at tasks that requires specialized or domain knowledge which the other person doesn't happen to have. And I'm pretty sure there would be tasks where same person would nX me.