The key is that they sold the game to PlayStation Plus and also Epic and basically boxed their game off from sales on both PC and PS5 by doing so.
Note that it's more than that, as happens often with PS/EGS exclusives: it's also not on Xbox (for 6 months in this case), and not on Switch (though it doesn't apply in this situation).
Most of those deals go for a grand slam where it's not on Steam, Xbox, Switch, and "free" on Playstation.
While they only get a lump payment, rarely linked to the downloads it will make on the platforms (good for devs on EGS in general since nobody buys there, much less on PS with situations like this) while the majority can't even buy the game on their platforms if they wanted to. Who buys games when it's EGS and PS+ only? No-one.
But as I said for a lot of other games, it's not even that one game that is important, failure happens all the time.
The next project is the big problem, they barely even released with two deals, then failed later... who is going to bankroll them after that? I'm sure big IPs and big devs can still find cash somewhere, but I don't see why Epic or some such wouldn't bend their arms in the process. They don't have a reason not to when their investment goes poof yet again and they are even less likely to succeed for the next game.
Being bankrolled by multiple companies and failing hard isn't going to help anyone in the long run that can't show results...