Why? Unless your needs/life change so much that you either need to move somewhere or want a fundamentally different property. (Which of course aren't uncommon.)
But, in my case, my needs haven't radically changed. I've updated my 200 year old house to be like I want it. I can imagine a lifestyle change but it certainly wouldn't be to another house in the same area.
"Wanting" is kindy tricky. How much money do you have? You can live in a new house every year...or hotel. But not all have that luxury, that's why I made that comment. You buy a house and you know shelter is almost solved (taxes+maintenance do cost but...)
And I did look at buying a Georgian alms house but the renovation was messed up and it ended up in the courts for ages
But can you imagine knocking it down and building a new one every 10 years?
When people don't move, their house doesn't get torn down.