Let me get this out of the way - I **love** URF. I didn't play URF until this years URF and holy cow it's so much fun. I don't think I've had such good laughs with my League friends in a while.
What_ isn't_ fun... is fighting the same champions over and over again. First time I fought an "op" champion in URF (i.e. Fizz/Ekko/Wukong), I thought,
"Wow! We just got rekt better luck next time!"
But next time, it was the same "op" champions and the game after that it was still the same champions... and the cycle continued for 20+ games. I don't dare pick someone "sub-optimal" (i.e. Janna/Aurelion) because I know that I will without a doubt go 0/10 in lane against one of the URF gods.
I know you can't win all the time, but you shouldn't lose all the time because you're getting tryharded on by people picking the godly champions.
I think URF would be much more enjoyable as a random pick like ARAM (including trades). There would be a lot more variety in games and a lot less tryhards.
URF is fun. Playing against/with same 10 champions every game is not fun. Make URF random pick (probably next time it comes around).
Less toxicity, more variety, more fun.
P.S. I'm picking Janna. I'll tell you how it goes.