At Christmas, Easter and several other times a year every one of our 4 bedrooms are occupied by son and family and daughter. At other times they are slept in by friends, and other visiting relatives. None of whom live close to us so need to stay over.
My parents retired to a 2 bedroomed bungalow and soon regretted it. Our children soon grew to big to share our bedroom and in adolescence, with a son and a daughter even them sharing a room was problematic. When my mother took up a creative craft that required table space, drying space and space to store materials the problems grew worse, In their early 80s they thought seriously about moving to a larger property but a sale fell through so they stayed put.
Of course some people do live in small properties and have no choice but to make glib remarks about houses 'that are too big and under occupied' just on a head count and room count is to seriously fail to understand the complexity of peoples lives, their interests, and family arrangements.
Shingles - Again. Have the Vaccine!