So other than the party system another change was introducing match making. Originally it was lobbies. You could randomly join a lobby and you were there until you quit. Meaning you played against the same set of people over and over until you chose to leave. I formed so many friendships that way and we started to fill up our lobbies with just regulars, then two or more lobbies. We all played against each other. Then matchmaking came about and really changed that. Now you wanted to match make to progress in the games XP or whatever.
As an example, the original Gears of War on 360 was a game where we all enjoyed playing together and even had a regular Thursday's gears and beers night. It was awesome and included a revolving list of 8 people and people in line waiting for a spot. Gears of War 2 came out and supported match making. It seemed cool at first going from 4 vs 4 to 5 vs 5 . What actually happened though, our group went from at least 8 down to 5 at a time. The reason was match making, the only way to progress in game XP was to play against another randomly matched team that would rotate between games. So our normal weekly event kind of fell apart. Now I get why we have it, no boosting and all in private lobbies etc. I just miss the days of playing people and making friends. Seems harder now when as soon as a match is over you go back in to the match making system and are put with another random group of people for a short period of time. I think that's why people do not invest the time or effort to be in game chat anymore. Every 15 minutes you go through the process of trying to see who has microphones and does not completely annoy you. Its just not worth it.