I'm Plat :3
In rank, yes, there is a notable skill difference. But I'm talking about all games, including normals. The majority just don't give a fuck.
TT becomes increasing difficult starting around Gold. It has more team comp reliance than SR. An example being, my team's first game into gold, our enemy went double smite jungle. In that situation, they held us back all game. More champs are also viable in TT, Karma and Leona are god tier. Objectives don't even mean much in the game. Turrets are nothing but something to do after winning a team fight. The alters remain neutral the majority of an equal match up. Vilemaw has also been brought down. It relies on straight up abuse of position and team trust.
ARAM, team fight experience? Imo, team fighting is about choosing your champs and complimenting each other. ARAM is about how well your team can control the situation they were given, if someone can't carry their own weight, they better hope someone else can. The way my group of friends practice micro work is spam playing ARAM. A constant stream of skillshots and need to not get caught off.
I honestly would love a ranked ARAM, just for shits and giggles.
My ign is PureNova. Course after the season ended, I'm letting a few friends use it to try out champs.