I'm actually wondering why do games like this happen, how? (matchmaking?)

Games when you end 3-3 and the rest of the team ends 3-26. I mean how does that actually happen if you're playing with people you should be playing with, how do people not understand how to not feed and die meaninglessly?

Ofc you can op.gg me and say but what about that game where you did so horribly. Okay I understand having bad games, but I'm talking the ENTIRE team, each person going 1-8ish. If matchmaking was rigged correctly how do games like this happen? Obviously I'm talking when I'm on the winning team as well, it's not fun to just completely stomp the enemy team, and then you have that one guy whose trying and actually doing pretty well and not flaming and you can't help but feel bad for him because his other 4 teammates are basically inting and flaming in chat.

What is this matchmaking? Poor quality games like this happen far too often in my opinion.