Truth. The closest I've seen to that lately is some competitive games, if you get a good team, but mostly in Arcade Brawls, which are made to be super goofball anyway, so people are just so much more chill.
As much as I like the way people actually try in competitive, why is it that adding any sort of competitive mode seems to make communities utterly toxic at a much greater rate? Warframe added PVP, and the PVP not only went toxic as shit almost immediately, it bled to the rest of the community suprisingly quickly. Secret world PVP is way more toxic than regular(But thankfully, has failed to bleed across to the rest of the game for the most part). Rocket League ranked took the community from fun-loving and friendly, to toxic and angry within weeks. Counterstrike and MOBAs, which started out as Competitive games, are famous as the high water marks of extraordinarily toxic communities.
I still try to be nice to people in Overwatch, though. If someone does a good job, I'll call it out explicitly, I'll tell people they fought well, encouraging people on my team, calling good shots if someone gets a good kill on me, things like that, going a bit beyond the usual "GG."