Junk yards only carry parts for so long. They generally crush and recycle stuff after a certain time. Sure there are still some backwoods places that still have a decent collection, But the vast majority of yards don't have that 2003 pilot gt anymore.

If you are really good at what you do you could avoid a lot of the mess by driving a classic. (Scouring junkyards)

The real challenge though isn't just that the parts will have tariffs; It seems like auto parts in general have taken a massive hit in quality

Yep “a parts”, you don’t like it take it up with apples keyboard I’m done fixing it’s “corrections”. No one’s fighting you on new car prices, but just don’t pretend gonna get away without paying the tariffs keeping your classic running.