It's entirely on you. You brought some valid points about how awful Cloudflare is, but that's not what got you banned. Your baseless claim of Cloudflare DoH somehow MITM SSL is. You are indeed spreading some FUD, even here by strawmanning what exactly you got banned for
keo
Censorship is not an answer, education is.
Even if you might not change their mind instantaneously, you will plant a seed of doubt (given your counterarguments are easy to digest and civil). Even if they don't want to listen, others who read your counterarguments will likely consider them. That's how I changed a lot of my stupid views by just reading other people arguing, but almost none by being directly in the debate (not immediately, at least).
Silencing them will only reinforce such views for them and for those who saw said silencing, that's how humans work (and for a good reason). It will look like you silenced them because you can't come up with convincing argument against their views and therefore they are right and you are wrong. Just imagine yourself at such position - they would think that you are brainwashed, not them.
There is also a downvote button exactly for that - spam, trolls and bad-faith arguments. If your vote is not enough, then point to others why you consider this to be deserving a downvote.
I know that it's easier to just get rid of these people, but that's exactly how we ended up with Gab and Voat. Correct solution is not always the easiest one.
Banning IP ranges is a terrible "solution". It hurts innocent while malicious actor could always circumvent it easily by using proxy/VPN/Tor.
My crude suggestion would be to restrict voting for new accounts (until certain karma threshold and time passed) like on HackerNews (one of the most civilized and helpful comment sections I've ever seen, lemmy has a lot to learn from it).
Additionally it could cost you karma to downvote, so unless you bring something useful to discussions once in a while, you can't downvote others.
Another option is to disable visible vote counter for everyone, so there would be little point in downvoting as means of harassment
Thanks for putting words in my mouth despite me explicitly agreeing that Cloudflare is awful.
If that's how you argue with everyone no wonder you are getting banned. The Mod that argued with you on Reddit had a patience of saint