Reddit's moderation system is among the best of any big platform because of how easy it is for people to start their own communities if they don't like the moderation on a particular sub. And these new communities actually will get traction if enough people are upset about the original sub's moderation - see the whole meirl vs. me_irl situation for an example of this. (There's also r/gamingcirclejerk vs. r/shittygaming - the original sub still gets more posts, but the large, active discussion thread community moved entirely to the latter because of the former sub having some crazy BS happen with the mods.)
You don't get anything like this on big centralized platforms like Twitter or Facebook. If you get banned by their opaque, highly automated moderation systems, you're just out of luck unless you evade the ban. The network effects and the costs of switching off them are just far too high.
Good moderation at scale is impossible[0], and the Reddit/Discord/etc model deals with this pretty decently by leaving most decisions to individual communities.
[0]https://www.techdirt.com/2019/11/20/masnicks-impossibility-t...