The PS5 is not actually yours, it belongs to Sony. They're just generously allowing you to use it to run very specific software you have licensed. They own the keys to the machine and they determine what you can do with it. Actually calling it a computer is an insult to the term, it's more like a video game playing appliance that happens to contain a computer inside.

Jailbreaking means taking control. It means unlocking the computer within so that it becomes a true general purpose computer. It means being able to run your own software, not just what they approve. It means being able to circumvent their DRM if you want.