US AOPA here
There are a few things I would add…
Mysteriously, you also get a load of avionics issues. I don’t know why, in cases where the obvious one (moisture) can be reasonably ruled out. Maybe it was sitting outdoors for years and put in a nice warm hangar just before going on sale, to make it look like it was looked after better?
IMHO the majority of aircraft for sale have not been flown for ages and few owners are going to have been paying for good quality hangarage for years.