I think this is one of those cases where optimization on the part of self-interested actors has ruined things for the rest of us.
It used to be that if one said, "allowing people to talk about obviously ridiculous things like conspiracy theories is fine, and important actually, because it's part of free speech," that would be pretty clearly true.
But at that time, the number of people actually talking about such ridiculous things was pretty small.
Since then, the number of people talking about election-related conspiracies has gone up precipitously, largely because of Trump and his supporters. Who, it apparently bears repeating, attempted an actual violent coup to force the election results to go the way they want them to, partly due to the constant repetition of the "election fraud" Big Lie.
So no, allowing these theories to propagate is demonstrably antithetical to the continued functioning of democracy.