I have to strongly disagree with you!
The physical complexities that it takes to rough in plumbing in a custom residential house cannot be matched by, any machine or robot not now and not in the next 20+years. Don’t even get me started on what it takes to do an old renovation.
If we ever go to a vacuum drain system like on cruise ships that might be different as long as we’re talking about gravity drains where pipes have to have a minimum 1/8” slope I can’t see robots crawling under houses with drills being able to do it anytime in the near future. They are either going to have to drastically change the way we build houses currently or come up with some very very sophisticated robots. I cannot see it happening in the next 20 plus years.
Modular and mobile homes maybe, stick built homes….It ain’t happening anytime soon.