Your early 20s are still late puberty. And even as an adult, you've still so much to learn.
But I'm willing to give the benefit of the doubt and say that he was calling himself a techbro at least semi-ironically. Of course in five or ten years' time, that too may become unacceptable, like ironically calling yourself a racist.
But, I was surprised that techbro has such a negative image too and used as an attack. Only found that out when I moved to Seattle. Sometimes it helps to adapt it, because for sure the community/locals on some level really do push it to a label.
Meanwhile, across the country in Florida - everyone encourages everyone to do what you want, learn, succeed and it wasn't rare that in university, outside university events IT/coders/artists and such all hung out together.
But, certain environments affect the meaning and acceptance of words. I still am flabbergasted that my experience in Seattle is still like that and that I was "shamed" for doing what I love. Seattle was the only place also that people in tech would also omit they work in tech and do anything, everything else.
These people were "finance bros" working in hedge funds before the VC/startup industry took off, and crypto became the most popular way to scam people.
Edit: actually the "overly analytical" might fall more into the stemlord category, who routinely get mislabelled as techbros.
But 20-somethings haven't yet got there and sometimes think they are in the top of their maturity and wisdom.
I guess it's life. One day they might look back and cringe on the idea of calling themselves "techbro" like if it was cool or something. And might say "what was I thinking?" Oh well :-)