>servants and house personnel

Which you mostly don't need today. You may have a lawn guy, take your car to a mechanic, and use a washer/dryer to do most of your laundry.

You actually need some help once you have kid(s).

Some people do have live-in nannies and au pairs for kids of a certain age but I'm guessing it's not very common, at least below a certain income bracket. People do use childcare and lean on relatives (or one parent just doesn't have a full-time job outside the house) of course.

Stay-at-home parent should not really count the same as servant or house butler.

Can and will happen again. I might even be a 'clever' underbutler to some misAnthropic Engineer

I think that could be true for some engineers. I'm skeptical it was true for the majority.

"Famous" engineers--probably. I doubt the person taking care of the steam engines lived in a fancy house. I'd much more expect the steamship owners and captains to live in that sort of property.