Imo stuff like mechanics learning is on higher-than silver division.
It's like karate. They don't teach you super-killer moves after you've got your second belt. In silver you learn how to cooperate & teamwork. And once you get the basics of this, then you are simply good in silver.
Now, I myself am in silver 2 or 3. But mu mmr level is for gold 2 (or it used to be.. Around 2,3k). I've lost my 2 promos. Not because I was bad myself (or so i hope). It was caused by TF 0/17 (seriusly, he just mashed at turret each time he respawned). Or Garen level 4 vs Riven lvl 7.
Problem with divisions is: it's teamplay. If one does bad, then winning is very hard. And then we have also afkers. If you'd clear all divisions of trolls and afkers then silver would change into decent division to be proud of.
Btw i've stopped playing rankeds after TF game. I just lost the will to play "serious games" when for every 1 good game i have 2 or 3 games with assholes that drag their whole teams down.