Speech is not comparable to nukes. Not even close.
I don't want everyone building nukes in their garage because nukes kill people en masse in an instant, and I cannot counteract the effects of someone else's nuke by setting off my own nuke.
People want the government to do their work for them. But you can't expect someone else to advocate for your interests automatically. The only relationship where that happens reliably on a regular basis is that of a baby and a mother. The government is not your mother. The government's policies are the result of the intellectual output of its citizens in a democratic society. You are supposed to control it as a citizen, to serve the interest of yourself and other citizens. It is not an entity that you can delegate decision making to and expect no consequences down the line.
If you think someone else's ideas are wrong, put forward your own. I don't think we should ban propaganda, as that would require a central authority to determine what info is/isn't propaganda and thereby creating propaganda in the process. I think we should ban the mechanisms that encourage the formation and snowballing of intellectually/ideologically homogenous groups on the Internet, thereby making it a hostile environment for propaganda and similar heuristics in general, so that the best ideas may thrive in dynamic competition.