Also, a lot of older people don't want big houses, and having easy access to amenities and socialization is more important than having extra empty bedrooms.
I will get downvoted for this comment: Size of living area does seem to be highly influenced by gender. I hear many more men say they would be happy living in a smaller place. I never once heard that from a woman under 50. (After the kids are gone, they may wish to downsize.)
Let me be the first one then - I am fully content on living in a 40-60m2 space with my partner and two cats. Considering we never lived in anything bigger this size is perfect for us, easy to clean and still enough space to live.