Depends on the kind of collectible and the kind of game it is, I suppose. Collectibles for my house in Monster Hunter is awesome.
Feathers in Assassin's Creed is not.
If I had to guess, I'm guessing it would add another layer that MOST griefers aren't willing to go through, but let's be honest... Look at the shit show here. No amount of ban control has to be worth getting your game delisted in 170 countries :P
It's not even much data at all. A game dev friend of mine took a look at what is shared through Steam's own API, and it's just a unique ID basically verifying that the steam account belongs to that steam user. The worst they can do with that is ask if the user already owns this or that game, likely just from the same publisher.
They probably just want the ability to better ban people if they are griefing other players (or make sure people can't cheat their way to more super credits)
The whole thing is such a nothing burger from sony's part, it makes it even more absurd that they're doing this!
Daaamn! Nice! I think the third one is the best one, but 4 is my favourite being that I grew up on it.