Is ranked play meant to be a joke, or...

I'm a support OTP. I play nothing else. Maybe that might contextualize some of it, but the fact that this is even a problem for support players -- if it is just support players -- is not something you should ignore. I'm sure you will, Riot, but... well, you don't actually care for your game, so what else should I expect?

The difference between the ranked modes in games like SMITE & DotA2, and League of Legends is just night and day. Broken-ass releases like Aphelios, Sylas, and Senna plague the game. Awful matchmaking has consistent 0/12 players & autofilled players going up against players in their main role, on their main champion. The presence of smurfs, leavers, intentional feeders & griefers has yet to be remedied to any respectable degree. The existence of freelo like Master Yi, Mordekaiser, Conqueror Heimerdinger (or Heimerdinger in general, really) and the presence of 3 teammates who either go slightly negative or extremely negative. All of these things lead up to ranked being a complete shithole, and completely unrepresentative of any kind of actual skill.

This feeds into my next point, which many may disagree with: all of this makes ranked as a gamemode completely worthless. I smurfed, got myself to Plat+, and it turns out that a majority of people there literally sum getting to Plat up as "it's just luck." Many of them, when I had explicitly asked about myself and how well I play, give me a generic "You look like you belong in Platinum, but what do I know?" and I just reply "Yeah well, it seems like I'll be in Silver forever."

Again, what purpose does ranked have, anymore? Just remove it. It's a pithole for toxicity. Unless you're in Masters, Grandmasters or Challenger, it's not really reflective of how well you personally play and apparently even the people in the higher elos are all becoming aware of that fact.