The PSN account, which is free, was required but turned off during launch. It's been working fine. Now if you don't link your PSN to steam you can't play after the end of this month. You lose a PC game on steam because you don't have a PlayStation Network account.
It's totally unnecessary and Sony has a shit cyber security track record.
Sony has shot the game developer in the face with this.
A couple friends of mine worked on the PS3 launch title "Lair" back in the day. Sony brass demanded, at the 11th hour, that they completely change the control scheme to use the braindead PS3 motion controller nonsense. The game wasn't perfect but, before that decision, it was at least playable. Game launch was a disaster. San Diego studio closed. Execs who made that decision probably got promoted. They've always been like this.