Average wage isn't $75k. That's average household, which frequently has two wage earners.
For individual full-time workers, it's $57,200[1].
For individual full-time workers, it's $57,200[1].
In my experience, this would be the case for cca 20-25% of the people I work with. So yeah, definitely not average - but definitely not something you never see. Every team has few devs like that.