I mean, defining "censorship" is kind of difficult.
You've got a stream of data, in the form of text, that is being added to a database. It would be logical to apply a 'filter' of sorts because let's be honest, there are bad actors out there (remember penis enlargement/viagra for example).
More and more of these filters are being done automatically, based on models of previously removed comments. You could try this yourself, create a simple application that submits 1,000,000 comments per second, of all sorts of varieties including links and disguised motives and try to decide which stays and which goes. Analyze your results, do you have a platform where the comments are meaningful/useful? Are you more "liberal" in allowing comments to stay even if they are obvious spam/unwanted content because "muh free speech!"?
If you're lucky, you may end up with something half readable, and not completely overridden with bots or content that is absolute meaningless.
Imagine if hackernews or other content sites didn't have the same measures, awful content would over run the site and make it less attractive.
All sites need to have some form of moderation. As a result, sometimes, content is removed. Whether that's "malicious" to you depends on your worldview.
I appreciate that moderating a large platform is a thankless task, you have potentially millions of comments each and every day, no human could possibly handle that volume of information.
Reddit is the same, automoderator can "censor" users, without them even knowing, and allows regex based filters, which may not be perfect but at least allow obviously terrible content to be removed before it's posted.
Remember, the bad actors (some might say russian interference during an election is bad) will always be trying to "game the system", so you need to constantly adapt your filters to try and be one step ahead in a cat and mouse game.
Just some food for thought not everything is "censorship".