Why is twisted treeline like this

my last few games on twisted treeline all have the same thing in common. my teammates are always new to something whether its new to the champ new to the game mode and recently someone who is new to the game. and its fine if there new to the champ. but how am i getting matched up with people who are new to the game. And the enemy team does not have this problem. They just get fed and win unless i manage to carry. my last game i had a Katarina who was new to kat, a garen who was new to the game. the garen died 12 times and we surrendered in the end. My level is 92 and kat and garen levels were in the 30s. Meanwhile the enemy team was level 60,level 86 and the last one was level 35. and this has been going on every time where my team is new to something and i have to teach them and find a way to win.