Can't copy files >1MB from PSX disc
I have a bunch of PSX discs that are about the same age as me and some of them have started to have issues. I want to create backups of all of them, but multiple methods aren't working. If I just use a regular file manager ("Dolphin", not the emulator), I get lots of "Could not read file" errors, seemingly for every file >1MB, so usually music and cutscenes. The "cp" command says "Input/output error". If I use "dd" to create an ISO file, it claims to succeed, but the resulting file is only a few kilobytes. And so on, every tool has similar issues. Some programs even freeze for a long time or forever when trying to read files. I've tried this with multiple different games, some of the discs look perfect on the outside.
Everything I've found online tells me that I should be able to just read all files regularly, the PSX just won't accept other discs if I burn them (which I don't want to do anyway). But I can't even copy. Are just coincidentally all my discs broken or am I doing something wrong?