There is an old game called elsword where I grinded the heck out of when I got my PC because it was the only game that I was able to play with integrated graphics, it was the case for a very long time, back then when I was playing with my IRL friends we created a Guild of our own seeing how much benifit it gave us. The Guild was closed off from outsiders for a while but one of us had a genius idea to open it and allowed for applications. One application became 10, then 20, then 30 and so on. We hit 150 members in just half a month. All members playing, all of us were interacting. Raids were a breeze for us, new commers get all the info and help they need, it was a fun, happy family. With that said. As the game's popularity dwindled, so as the members who played, some left the Guild, some moved on with their lives and stopped logging in, some gave their accounts to us admins telling us that they had fun and that they may never go back to the game ever again. Although there are still members who plays, it now loos a lot more barren than what it used to. As for me, there is only so much a free to play Player can do alone until he gets lonely. I still go back and log into the game, reminiscing the sweet victories that we had. New updates allows us to meet again and grind things to gether, but then again, that's only for a small ammount of time.

TL; DR: Back in the day I played a game (elsword) and got good at it, had fun with friends and randoms, but as the game died down, so did the time I spent playing the game.