As a former League player i felt kind of like that back then - a lot of people were just not nice people. I think some of that comes down to how certain PVP players are motivated insofar as personal agency - they want to be the high carry, they want to be why things won the way they did.

I saw that too in Overwatch 2 when that first came out with the rebalance to 5v5: suddenly everything was about personal agency and Blizzard decided that the game balance should favor that over strong teamwork (IMHO).

For me, that's why I got out of those two games and only play when I have nearly a full team of preexisting friends. I was always more focused on trying to get the team to the finish as a whole (maybe that comes from ending up as a support main).

Ended up finding my vibe in FF14 PvE, where everyone tends to work together better. That's not to say there aren't bad apples and problem children in a game that has minimal anticheat, but on average I feel like I see it a lot less - and fewer people who swear you out for just learning something new, where the general populace will often take time out of their own schedule just to help people along or explain something tough.

Sportsmanship isn't dead, it may just not be where you're looking.