Boosting in TFT

why are you allowed to party up in TFT, i have seen plenty of people boosting eachother, make it a solo game mode, no friends allowed, for ranked, or 1 max like soloq, its stupid riot didnt think it would happen, yet i have seen it many time, played a game a 3 people are on sub level 10 accounts, and when they vs a specific person the sub they tier 2s for tier 1s to gurenntee someone stays winning, or they all just cuck the pieces you need ensureing one of them hits top 3 because you cant get the pieces you need, TFT is so bad atm still to much RNG, free gold over an item? wowzers