I don't see any disc based games going as crazy as carts. There will come a time when the discs simply wont work. Regardless of scratches, disc rot is a real thing. You could leave a game sealed and the odds of it working flawlessly in 20-30 years are minimal. Also - the consoles will all be dead someday. They have too many moving parts, too many things to go wrong, etc. That PS2 might have a brand new laser installed, but it might not be functional in 20 years even without use. Are there going to be lasers available 20 years from now? Meh - maybe, maybe not.
My suggestion (even as a collector) is to back those discs up on a PC and store them away until you want to play them again. I have a HDD installed on my PS2 for many reasons - one is because I know that someday that could be my only option.