How does one quantify that? Reddit moderators have a reputation that they themselves created. I'll tell you what, go ahead an post something (comment or topic) that goes against the prevailing group-think in any reddit sub, and you'll experience it for yourself. Record in a spreadsheet, and you'll have your hard data that supports reddit as cancer. As reddit moved away from free speech, and more towards totalitarian speech control, I honestly couldn't hope for a faster collapse or conflagration of those echo chambers.
I’m sorry but the scale that Reddit is at now and the number of subs that have large and thriving communities tells me that moderators aren’t creating some hellscape preventing community from forming.