ADC is such a team reliant role. Yes, it's badass to 1v5 carry as an ADC but it's only really effective when your team can play with you (not just around you) which rarely happens in lower elos. Gold II+ introduces Plats who can play now.
But with the new ranked system, this doesn't really work so ADC mains really get the short stick.
(This is in terms of just climbing fast and ranking. If you're already really experienced at the game, it should be a relatively fine grind)