A lot of developers really don't travel a lot for work if they don't speak to customers much. And it's not uncommon that a developer/sysadmin may get to go to one conference a year or something like that.

Certainly some people I work with, whether developers or other roles, are traveling all the time. But it's not everyone.

No, I go to big conferences less than once a year. I've lived in multiple EU countries, and never worked anywhere where a common developer went to conferences regularly. Didn't even realize that was a "thing" except for a few people who were known to give talks everywhere.