What gave you the idea that there is an end-game? The social dialogue is never ending.
Then this is a denial-of-service attack. Bad-faith actors can hijack the public conversation forever by simply refusing the budge. The public conversation then becomes a free and indefinite platform for them to spread propaganda, and any attempt to change that is portrayed as a great evil.
You can't consume every possible idea. You automatically filter them, most of it subconsciously, just like everyone else.
‘Never feed a troll’
How do you think these critical masses around _specific ideas_ are formed? Qanon isn't a whisper campaign.
A thought experiment: we burn all books about Area 51 alien stuff. The whole myth would probably die along with our generation. There's no more stuff reinforcing it, no large traces. No more grainy photos.
That original quote might work for a general ideology but I don't think it works nearly as well when applied to specific narratives.
(Of course this works in all directions, see the obliteration of socialist movements in the 50s and 60s)