If the size of influence of the entity limiting speech is the issue, then would a mod of a very large subreddit banning a user be worse than a comparatively sma

If the size of influence of the entity limiting speech is the issue, then would a mod of a very large subreddit banning a user be worse than a comparatively smaller, private social network de-platforming a user? I guess my point is more so where do you draw the line? Legislatively-speaking? By the size of the community?