“You obviously don’t know the mysteries one can run into in the plumbing of 50 year old 10 million dollar homes.”
I was amazed to find that the cast iron drain pipe of my 1978 Florida home was joined by molten lead.
Fortunately, my cast iron pipes are still good.
Quite often the plumbing of six-decade-old Florida homes needs total replacement.
Lead and oakum is how all the cast iron pipes used to be joined, if a 60 year old house has a bad section that has to be replaced you jackhammer up the floor and replace that section, you don’t replace everything, not even if the house has a raised foundation.