I've been interviewing for multiple companies at all scales for over a decade in the US. Hiring lawsuits just haven't been a factor.

It was years ago, but I think I might have taken a half hour interview training session at a large company that was along the lines of "Don't ask about age, marital status, kids, etc, but it's fine if the candidate brings it up first. Use your best judgment." That was about it. I could also be mis-remembering and that could just have been something my manager at the time told me before throwing me into the interview rotation.

So I think calling it a legal minefield is stretching reality by quite a lot.