Depends on the country, I guess. In Europe, it would definitely not be the norm and I would definitely call previous employers if it was several 2 year stints.
While I absolutely confirm that everything you said is true, it’s interesting that that call would be illegal in many European countries. And in many more you would at best get a „I can confirm this person worked on this position in this timeframe“
Europe is not a monolith. Lots of short stints is not unusual in London.
Europe’s labor market is sadly still mostly out of touch with how startups work. It’s stuck in the last century. I’m not sure if this is due to tradition, or due to the fact that startups are much harder to start in Europe in general, so people on both sides of the hiring process have less experience with it.
Two years is more than long enough to join a startup, build 3 things, and see that your equity is never going to be worth anything, and find a new job. This isn’t anomalous or weird.
If you're really in Europe then I'm sure you know that calling previous employers is completely pointless, the best you'll get is "yes this person has worked here before".
And I work in games and 2-3 years at each company is pretty normal, with some exceptions people just finish a project and then move(or are let go, unfortunately). YMMV of course.
2-3 years is pretty average tenure inside the EU tech sector for the past few years [1], but regardless I don't know what that tells us, given that nothing else about this is average. The sample size of Andrej-sized talent in an ongoing tech revolution of epic proportions is just very small.
[1] https://ravio.com/blog/employee-tenure-trends