Why are people even allowed to bring groups/friend into TFT matches? all its used for is abuse

After seeing some chinese coordinated troll group who purposely took key items from every other regular player. they all had some group tag names of KOT3X and chinese user names. none of them spoke an english word even after 2 of the other normal players(including me) in the match kept asking them questions. only one guy responded with some chinese. look im not pointing figure's there are probably coordinated NA troll groups who do the same but. i'm just wondering what is the point of bringing friends and groups together in TFT? What is it used for but abuse? Like whats to stop each of these players from doing their best to help one or two of their guys from reaching top 3? like how do you handle something like that? could you imagine if people could go into summoners rift and have 3 people on their friend list always guaranteed to be on the enemy team? you could literally just have those 3 people do everything in their power to make sure their friends win! as thats what just happened to me now. so story is i was playing ocean mages. i had an early spatula and every time i'd see a mana crystal available on the circle one of these KOT3X members would take it from me. i actually looked at what comps they had and none of them were playing comps that needed mana crystals and it didn't fit with their builds so the only answer is they were purposely trying to make me lose. and funnily enough every one of them that took the mana crystals from me dropped out really earlier but not before ruining my gameplay experience.(and one of their KOT3X ultimately won that game in the end;mind you there were only 3 total regular players in this match) that is just not something any TFT player should go through. there is no way having coordinated groups in TFT creates a positive gameplay experience. so please riot i ask of you to remove the option of bringing/queuing with friends/groups in TFT. or atleast explain why this feature which has no positive gameplay experience still remains in TFT?