Moderators are there to ensure the community thrives, not to respond to 50 restatements a day of "COVID-19 is a hoax" by people "just asking questions".
Part of that is very much ensuring that the front page is not wall to wall conspiracy theories, and members don't have every thread inundated with the same junk.
So each time a post "just asking questions" is posted, close it with a link to the explanation of why the idea has already been debunked. Just like a Bugzilla dupe or a StackOverflow dupe.
For a long time, Reddit moderators did not have the tools to do this. Regardless, whenever bad-faith argumentation is removed, the person whose comment was removed paints the event as censorship which just backs up their conspiracy argument more
Spam detection has been a feature of email clients for a long time. I'm sure even a rudimentary automated detection mechanism could prevent a significant portion of the dupes.
In order to have a good community, you need a form of censorship, whether through moderation, spam detection, voting systems, and so on. Otherwise, the community as a whole becomes a mess.
Part of that is very much ensuring that the front page is not wall to wall conspiracy theories, and members don't have every thread inundated with the same junk.