It really depends on where you are in the world. Poorer countries often have older aircraft that are in worse states of repair. Most aren't exactly rust buckets, but they wouldn't be legally airworthy in places like the US or EU. This does result in worse safety records, but it's still safer than driving the same distance in most places.

Lots of private planes from the 70’s still being flown, there’s a little cosmetic rust..

Those are getting overhauls in regular intervals though, it’s more like theseus airplane. Except for the structure itself, there is a lot of repair and replacement happening. And they also have a less-than-great safety record (although that is also pilot related).