I'd like to see the poll is you have the source btw as I apparently didn't get to use it (wonder why) Also, the community has had ample time to accurately gage the system now than the had previously.
Okay, i'm making issues? Riot tested it out you say? My god, then it must be balanced. Uh huh? Feral flare, ekko, Literally every item/champion they've nerfed right after release Cough Cough Xin Zhao Cough Cough, because their testing was that good. The list will go on for days btw. But if that's just happenstance or irrelevant let's look at something more logical and serious.
Back a year ago or so, if I said I wanted to play as a solo player with 4 others (not grouped or coordinated in the slightest) in Ranked Teams, you'd say I'm crazy. It would never be something most players would ever want to do because it's essentially you throwing LP away. Yeah, that's a wonderful plan. Let's force everyone to do it against their will, because this is what a good competitive game looks like.
Let's take a look as to why the system was created. Friends!!! Oh boy, I can't wait to decimate the enemy with my 4 "friends" from "school." Wow, I'm going to get to diamond in no time, it's like they're not even trying to stop us from winning. Oh buddy, I love this new system, it's so easy to manipulate. You mentioned problems in SoloQ, yea remember when boosting was illegal? Good times..... This is just a culmination of giving people "what they think they want" without worrying about the consequences.
Finally, if the system could work at even a 50% intelligence rate that would be pretty decent all things considered. If no-one abused the system it would work, if there were no 4 man teams the system would work. If there was no DQ at Gold+ the system would work. So many "Ifs" but there are too many "buts" as a result. You may say soloQ had it's issues, and you're right, but the issues there were nothing compared to the current unsolvable problems that plague DQ.
Rambling, mildly incoherent, but the point of DQ being of terrible design to cope with "friends/Elo Boosters" is disgusting at it's core. It's great that you have friends an all, but in a competitive scenario, even in real life you'd likely pick the best people whether they're your friends or not.
(If you had to play basketball with a dream team, you'd probably pick Lebron or Shaq back in the day, not your classmate who's just pretty good.) The system is terrible, stop defending a retarded pony, putting it down is the best solution for everyone.