If the battery dies, it would be unable to verify if the gamer owns the game and thus would prevent them from playing it. While these batteries do last quite a while, it is rather annoying that a battery that only costs a few bucks dictates whether or not you can play games on a console you paid for and games you probably spent hundreds on.
However, it appears that Sony has quietly fixed the issue for both the PS4 and PS5, where in a video by Hikikomori Media, he has tested it out and discovered that even if the CMOS battery is removed, gamers will still be able to play their games. There is a small exception and that is it won’t work for PlayStation Plus games.
This makes sense because for PS Plus games, technically gamers do not own these games as the license is only valid for as long as they are subscribed. Since the console is unable to go online to verify their subscription, it prevents them from playing it. However, apart from that, digital games and physical games don’t appear to be affected.
So far we haven’t really heard of many reports (if any) of the CMOS battery dying on the PS4 or PS5, so while this doesn’t appear to be a huge issue, it does have the potential to blow up, so it’s a good thing that Sony has addressed it.