i think its a mix of things besides smurfs being one of the obvious issues.ive seen players in my games that dont understand the basic concepts of the game like csing and warding.i was silver last season and placed bronze s9 just about every game goes as follows,my team will get a mix of unranked new players,actual bronze players and enemy team will have a gold smurf in the jungle that hard carries the game cause nobody that low knows how to not overextend,chase.the smurfs for sure have a heavy influence on the game if the teams consist of actual bronze skill level players.but as far as i know in 5 years of playing thats always how ranked has went.but from what i remember it was once i got to silver is when the smurfing was a lot worse i guess due to a new account being placed silver.id add the suspect person to friends just to ask them and sure enough they were plat on their main account lol