

Well, we already have the proof, because it was broken on PS5.
If Sony had held firm on a PSN sign-in for Helldivers 2, it would have been just as borked on PC as it was on console. Ditto for if Sony had retained its log-in requirement for singleplayer games: You could effectively play God of War Ragnarok offline after creating or logging into a PSN account (unless you opted for a handy mod), but just like installing a PS5 disc drive, a PSN outage would have prevented first-time setup of something that simply does not require an internet connection.
I wouldn’t be surprised if it uses an internet connection to verify the disk to try and prevent used sales or pirating