I don't know the science. I DO know that movies/games on disc won't last forever.
You should get plenty of years of use out of your collection, and hopefully your movies/game system will become obsolete before the discs deteriorate, but they're not something that are designed to last indefinitely.
My kids were big into copying music onto CDs when the capability first appeared, and commercial discs last a lot longer, but the
ones my kids made way back when, are turning-up inoperative, one-by-one, now.