That’s exactly the reason. I know that some of the elites have stated that communication is not required in a good team, and that some of them preform just as good without mics as they do with them; but that doesn’t take into account that they play with said people all the time, and that all of them are just naturally strong. Playing solo with randoms whom you don’t know will ALWAYS put you at a severe disadvantage without communication, against another team of equally skilled randoms who ARE communicating. Hell, i’ve played with randoms who ended up taking a FANTASTIC team comp, so that whenever i would see a known pre-made of lesser skill take a sh*t comp, i would think “oh yeah… We got this!”
We wouldn’t have it… You’d see all the telltale signs of a communicating team (rushing to save each other, chaining CC, backdooring together, etc.), and even though it would be a close match most of the time, we would still lose due to the cohesiveness of the other team.