Premades are literally ruining this game

OK so this is pertaining to under lvl 30s. When below 30 something has to be done with premade groups. You basically have the following senerios happening way to often.

1. High elo like plat and above is duo or trio with some low lvl player so you get game with some plat diamonds and some lvl 15s. This is just flat out not fun. Should be restriction on who under 30s can play with.

2. Premade group basically hijacks game and thinks they can take whatever role they want and play whatever champs they want where ever they want and its fine.

3. idk thats it