Yeah, it varies.
My house was built in 1959. I bought it in 1997. The hot water heating system is original. The pumps and some of the plumbing have been replaced. When i bought the house the inspector said, “it’s past its expected lifetime, but i don’t see anything wrong with it.” When i replaced some plumbing this year the new plumber expressed surprise that it works, and i probably need a new one.
The hot water heater gets replaced every… Maybe 7-10 years?
We’ve bought several dishwashers.
I bought a new washer and dryer when i moved in. Recently replaced the dryer.
Replaced a lot of the plumbing as part of a bathroom remodel. That was at least partly because the plumber wasn’t willing to work with cast iron, which is what the “out” pipes were. (Water comes in via copper, and none of that was replaced.)
Installed AC long enough ago that i expect to need a new compressor soon, but so far I’ve only had to replace parts the chipmunks damaged over the winter.
The fridge I bought new when i bought the house is doing fine. I have a friend who went through 5 fridges in three years. There are lemons on the market.
I don’t remember why we replaced the stove. I think just because it didn’t hold a steady temperature and it was hard to bake. The new stove shows no sign of needing to be replaced.
Houses need to be painted regularly. (exterior). I need to find a painter.