Matchmaking prevents from getting higher ranks? Should matchmaking system be revised?

My story (you can skip this paragraph if u don't care): I'm playing league for quite a long time and consider myself belonging to sth around G3 but I can't advance past S4 this season last season I think it was S3 and S2 one more season before (I play mostly solo Q, fill (what currently means supp)). Around 50% of games I can consider being even, 30% enemy team crushes mine, 20% my team wins with ease. I have ~ 50% win rate and now I'm litterally stuck on the edge of S4 and S5 (win 1, lose 2 (drop to S5), win 2 (start series to S4), lose 2 (fail series), win 2 (series starts), Win 1 (promoted) and after few games cycle starts again). The biggest obstacle is that I'm matchmade mostly with ppl that I'm better than (at least from what I can deduct from this one match (lower number of games played, worse stats, less gold, etc (leave alone the leavers, DCs, flamers, and 'mid or feed' kinda guys)

I think that a lot of ppl suffer because of current matchmaking. I hope to bring riot attention to this issue. Please participate in the poll and leave your comments.