Ranked Bronze Question

So I'm only a few games away from finally reaching level 30 and starting ranked play, and for a long time I've wanted to play ADC and support roles because those are the two that I've played the least. Why? Each time I go into a blind/draft game as an ADC or support, unless I'm pairing with a premade friend, I always get bad ADC/suppport. For example, as ADC, my support constantly stealing my CS, recklessly jumping into fights without warning, roaming off into jungle and other lanes and not actually supporting, standing back while watching me die in a 1v2 that could've been won had they gone in with me, etc. and I constantly lose lane because it ends up being a 2v1, sometimes even 3v1 because of my support feeding the opponents. As a support, I get ADCs that don't even try to CS, they just let the autoattacks go through and barely get any gold, they go too far in and get poked to death, or they try to, for some reason, all-in and end up dying and feeding the rest of the game, and because I'm a support without much damage potential I end up being basically useless because my ADC's being dumb. I've literally had supports who refused to support me because they either didn't like my champion, or they wanted to farm instead of me, or other retarded reasons. Does this also happen in ranked, or are players at least decent? If it does happen though, when does it stop? I currently don't have a friend who mains adc/support so I'd have to do it alone, but if bronze players are also as bad then I'd rather not bother.

I'm definitely not the best player in the game, I'm actually still pretty far below average, but at least I know the basics of playing roles. I know how to farm as an ADC, and I know relatively well how to help my ADC farm as a support (still working on this, as I haven't played much support), but when I get a teammate who literally has no clue how to play their role and/or refuses to even try, it's frustrating. Of course, this doesn't happen all the time. I've gotten good carries and support before, but the worse alternative happens nearly 50% of the time so I just stopped playing those roles altogether, unless I get autofilled into it(I usually don't like dodging games).