The majorities decisions and perspectives have historically been true/popular/right.
A large number of reddit users comment to engage and add to a discussion. The same way a group of people come together in a conference room or auditorium. As with those places, there are differing opinions in the comments, but a general consensus of some kind. You may hold different opinions, doesn’t mean others are in league together. No “circle jerks” or “echo chambers” (people need to quit using that phrase) in most legitimate threads. Just common thoughts and opinions.
Reddit can be brutal. It’s not for everyone. Don’t take the insults/karma personally. I upvote you.