Well I think it's nothing more than a social norm, and an easy one to avoid at that. People are mostly asking what's your job because that's a standard icebreaker.
Since I (mostly) recovered from burnout, and learnt that I'm actually not my job, I took the habit to never automatically ask people what is their job, at least not for ice breaking.
You can talk about their hobbies, their kids, their tastes ... because those are the real topics that will define if you bond or not anyway. And yes some people sometimes do have an interesting job that is worth talking about but when it happens, you will inevitably talk about it anyway.
You have that backwards though! :-)
We'd get to know people in our community, often because they were born in to it, then we'd fit in to productive roles.
The way we do it these days is a recent, post industrial revolution, mode of society.
I’ll add that if you see your colleagues as anything else than primarily working for money, you’re a bit delusional unless you know for a fact they could not work for the rest of their lives and be financially fine. Of course there are other reasons to work than money, but the way the system is set up you’re not supposed to care more about them than about cold hard cash.