Is Climbing the Elo ladder as Support "RNG"?

I've been playing league for a while now (I think nearly a year) and admittedly I've had some bad games here and there. I noticed once I dropped to around Silver 3 though it becomes insanely hard to climb the elo ladder as support. A lot of times I'll have an amazing game with high assists, low deaths, most wards placed, most wards destroyed, great communication, etc. but it's still not enough to win. Right now I'm at Silver 5 after dropping hard and I feel like most of this game is just RNG based on what teammates you get. Like literally I'm ready to quit this game just because support is so suited to my playstyle such as being a shot caller and having a great kit while supplying my team with in-game knowledge of where the enemy is and what a good or bad engage is. The problem is Silver 5 is so toxic there's not much I can do as support and people don't listen anyways.

I've gotten tons of matches with 4v5 on my team or even people just having no idea what they're doing like building AD on an AP champion. I feel like the only way to get out of "elo hell" is to just switch my role to a carry position till I'm like Gold at least, what do you guys think? I'm great at landing skillshots with multiple kinds of support from champs that do not much damage like Janna to tanks like Tahm Kench or even high burst like Vel'Koz. I have around 12 different supports I use in different categories such as: Tank, AP, AD, Burst, Sustain. I normally pick a champion based on my our team comp or countering against the enemy team comp. The problem is since I've done hundreds of games as support champions I lack skill with other champions and csing my lane when I'm mid or top.

Here is a list of supports I normally use:

Taric, Bard, Soraka, Blitzcrank, Braum, Nautilus, Thresh, Alistar, Janna, Sona, Morgana, Tahm, Lux