edit: this is regarding normals
The one fucking thing Riot cares about is making sure you never stray too far from a 50% win rate over the long run.
They don't care one fucking bit as far as I can tell how enjoyable a match is. I don't keep notes so I have nothing concrete here, but the FEELING is most games are a fucking one sided stomp for the winning team.
I look at players ranks every single game, and you can see a big obvious trend. If you start losing to many they manufacture a win or even a win streak by giving you either shit opponents or higher level team mates, either or. If you start winning too many, it goes the other way, where they either put you up in a bracket you don't deserve to be in and you get beat down, or they give you lower ranked team mates.
I usually am a mid tier silver player.
My last 3 games my whole team was either unranked, bronze, or low silver, against teams that always had at least one gold player, and all 3 enemy teams barely had any or 0 bronze players.
I'd just play ranked to avoid these fucking lop sided teams but I want to play champions I'm not practised on in normal. Why can't Riot spend more than zero fucking time trying to get more balanced teams?