Firstly it naturally created echo chambers, both using subs and the upvote downvotes system.
But also that system can maybe affect how people think . So unpopular opinions can be downvoted, even though the person isn’t wrong. And popular stuff gets s upvoted even if they’re wrong.
So that person and others may question that opinion’s validity. Slowly their opinions may change without them realising it.
Combine that with the fact most subs become echo chambers. It’s a bad mix.
And once a sub becomes an echo chamber, a sub for those who have the opposite opinion may pop up, it’s self an echo chamber.