With a printing press, you have to procure materials, a printer, wide distribution of physical items, etc., and all of those contacts mean that someone somewhere can probably point fingers if the law wants to find you. But try finding the people behind the 10,000 anonymous Reddit throwaway accounts, half in foreign countries. Or the guy writing fake news articles that get picked up by Twitter, who paid for his hosting account in Bitcoin and lives in Thailand. Radio is more anonymous, but can't be instantly shared in the same way things can online. A friend would have to tell you the frequency, you'd have to make time in your day to tune in and listen, and if a pirate station gets shut down there's not always another one lined up to take over instantly.
That's the problem here--nearly free, instantaneous, global, mostly anonymous communication, that friends and family can share into your inbox instantly and effortlessly. Firehose after firehose turned on, aimed directly at you, by people wearing masks. That's why this situation is different from the printing press or the radio.
Or you'll just say "twitter ain't for me, gonna go for nazi mastodon".
Infowars exists, there's always going to be a platform for these people, but it's more about making their efforts less worthwhile in other parts of the net.