Well if it can replace senior software engineers... Wouldn't it also be able to do almost all of the other jobs? Or are you referring to some specific future where AI advances massively, but robotics does not and handymen are still safe?
I'd say if all humans are unemployed, society would change massively. We can't really tell how that'd work. But if machines / AI do all jobs, get food on the table... I don't really know what other people would be doing. I think I'd relax and pursue a few hobbies and interests. Or it'd be some dystopia where humankind is oppressed by the machines and I'd fight for the resistance.
But regardless... In a world like that, money wouldn't work the way it does now. Neither would salaries for labor mean anything.