That's funny because I think that was around when I played. I only ever played with at least a duo though. I'd almost never play on my own. Not because I couldn't play well enough, but because I didn't want to have to deal with people alone.
I enjoyed my time (not all of it but some) and watching Arcane made me miss it. But I don't think I'd go back to league. Maybe tft and we'll see how the mmo does.
This! I've always had super friendly interactions with Genshin co-op, even when searching through the co-op tab rather than looking online (aside from one kid I had to kick because I was not going to buy them a welkin lol). The only time I've come across problematic behavior is through social media. It's also very popular so of course on twitter and reddit there is going to be a large loud volume of immature people, but that's most games. In game people are usually good.