My sense is that third-parties were told not to bother or don't worry, XMB/PSN would provide a universal friends list and communication.
EA used to have their own lists and while in the lobbies of one of their games, you could see your friends and arrange games. This was on the PS2.
On the PS3, they get rid of all that (even though you could log in with your EA ID on their web sites, the one you actually log in to get into their servers). As a result, communicating on the PS3 is WORSE than it was on the PS2, for EA games.
The only way people find each other is to drop into XMB and send messages back and forth. EA used to at least support text chat while paused in-game. No you have to use XMB now, find the name of the guys you're playing with if they're not already on your list, then type a message, then wait for a reply instead of seeing the chat in one screen.
Launching games is ridiculous too. You have to use XMB to tell a guy you want to play with which game you're trying to join.
The XMB/PSN was suppose to provide a universal list and more centralized messaging. But it seems the developers just dropped whatever messaging support they used to have and assumed Sony would fill the void and what effort Sony has put in is inadequate.