Isn't the exact opposite true as well then? If one side is siloed, by definition the other side must be in an opposite silo. You've taken it upon yourself to define that your side is in the "public debate" and therefore somehow isn't just "talking amongst themselves". Don't you see the issue here? Left Twitter/Reddit/Facebook absolutely exists, and they are not meaningfully conversing with the other side.
And, if anything, having a sitting president on your side should by definition mean that you are "part of the public debate", since everyone at least hears the president's words (and especially Trump's).
Propaganda is in the very nature of communication and because of the internet it has allowed special interests to capture the attention of potentially millions and instill extremist ideas. For free speech to work propaganda must be employed and countermeasures must be employed. Free speech doesn't mean giving equal weight to all ideas, just like equality of opportunity doesn't mean making everyone equal all the time.
You're right. And no offense specifically to anyone here, but he's trying to make his point somewhere with a specifically curated silo.
One of the logical fallacies from pro-free-speech defenders of these people is the assumption that these ideas were organically developed. But I can assure you there is propaganda and foreign and domestic special interests that are intentionally shaping the thoughts and ideas from these people. I know in the Chinese community that interests like Falun Gong (an organization that believes extra-terrestrial Aliens are manipulating humans to intermix racially in order to subjugate us as well as other less-than-progressive beliefs like homophobia) have been heavily pro-Trump because of his anti-China policies, and they've been putting out a lot of toxic content aimed at Chinese-Americans [1] [2]. This is a disinformation war and taking actions like this is a part of war, otherwise services like Twitter are just complicit in aiding misinformation campaigns by one side.
[1] https://www.washingtonpost.com/world/2021/01/07/trump-qanon-... - Falun Gong organized "Stop the Steal" protests in Taiwan
[2] http://www.asahi.com/ajw/articles/14013938 - Same Falun Gong protests in Japan