Many aspects of any home that you might purchase will likely never need to be replaced, for example...

[1]  the foundation

[2]  the wall framing

[3]  the plumbing

Some items may need to be replaced at some point but when you choose to do so will be more elective than necessary...

[1]  flooring

[2]  interior paint

[3]  light fixtures

But... some items will definitely need to be replaced at some point in your home's lifetime (or multiple times in your home's lifetime) and as such you should consider how soon they will need to be replaced when contemplating a home purchase.  These "definitely will need to be replaced at some point" items are...

[1]  roof

[2]  heating and/or cooling system(s)

[3]  water heater

[4]  kitchen appliances

If you're considering the purchase of a home that has recently had all four of those items replaced... great!  Alternatively, if all of them are 30+ years old... not so great!

Ask about the age of the main systems of the house you are purchasing... preferably before you are already under contract to buy it!