https://wccftech.com/ps4-no-offline-games-cmos/

Last month, well-known hacker and modder Lance McDonald suggested that(you know him from the unofficial Bloodborne 60FPS patch), in a few years, PS4 players might not be able to play PS4 games offline when the CMOS battery inside the console dies. Fast forward a few weeks and a Twitter user has now posted proof that this is indeed the case.

Twitter user Forest (@Forest_Reviews) decided to purchase a PS4 Slim model to test whether PS4 games will no longer work due to a bad or missing CMOS battery without an internet connection. “I went out and picked up this #PS4 slim in order to take it apart and remove the battery inside of it, Forest writes. “This test is to determine what will happen if the CMOS battery goes bad and pretending the PSN servers are offline. By replicating the issue, we hope to have some record of it.”