Echoing SpaceJammerSlammi and some others, it’s mostly been MMOs that have made me feel this way. EVE is one in particular that, while there were some good and memorable times, I still felt very much “left out” of mostly due to the time investment.
It just seemed to me to require such a substantial amount of time to feel like I was contributing enough compared to everybody else in my corp. As I had less and less free time on top of being burnt out on the game (I want to try new stuff!), it eventually became untenable so I left for good.
Also, a lot of players there were just… not great. Nowadays though, I thankfully have a much better way of thinking regarding all that stuff (being part of a group of friends in a game, community, etc).