Lately i have started playing 5 stacks. we are currently all around asc3/low immo elo.
However, 90% of our 5 stacks were horrible matchmaking. why? i shall give you the 2 worst examples.
the absolut worst experience was a lobby with a ragehacker. a reyna shooting through smokes and walls, dropping a 50 bomb. after checking tracker, the enemy team was 3 immortals, (immo 3/immo 3/ immo 1) and their reyna silver. their so called "immortals" played like dogshit, even going negative kd against us, while getting carried by a spinbotter.
clearly the reyna boosts them with different accounts, cuz all of them had a winrate of about 95%+
second worst example;
again, average asc3 5 stack. we get 1 immortal 3 player against us and the rest was low gold/plat elo. However, the gold and plat player were smurfing, cuz they carried the game super easy. (i dont think they were cheating, just smurfing)
so they were abusing the matchmaking system, which tries to even out the average elo, but used low smurfs to boost this one account to radiant.
its so hard to climb in asc/immo elo, because riot doesnt understand how easily their matchmaking can be abused.
when i played csgo (i was global) around 6 years ago, atleast steam fixed elo boosting and changed the matchmaking so you couldnt pull shit like this off. Riot take notes and change it too, please. its frustrating as fuck.