I am in Gold 2 right now and the amount of Jett/Reyna smurfs I encounter on other teams is ridiculous. 100% of the time they are below level 15, which is a huge red flag. I will go to their tracker.gg accounts (if they have them publicized) and they'll have multiple 25+ kill games.

Requiring players to be Level 30 (or 25, whatever works) will definitely decrease the number of smurfs. I'm not totally sure how MMR really works but I'm assuming they would be forced to play unrated (to get XP) which would increase their MMR as they do well. I know 10 wins are required to unlock ranked, but there should also be a level requirement.

No one level 12 or level 5 should be able to play ranked. It's fucking insane how people can just freely make accounts and hop into ranked at such a low level so they can shit on people 2-3 tiers below them.