I don't see why anybody would doubt the existence of those trolls. It's quite obvious that social media can be cheap and efficient tool for spreading propaganda, and information warfare / spreading propaganda among your enemies is nothing new. It's done by many nation states and other actors, Russia is just among the most successful.

Anyway, I tend to agree that "too much" freedom of speech is not the real issue here. Across Western world, neoliberal economic policy has failed to bring prosperity among large segments of population. Politicians have also ignored very real issues, such as failed humanitarian migration policies, DEI-policies which discriminate against particular "privileged" groups and so on. Trolls would have much lower success rate, and far right parties would be much smaller if these concerns had been taken seriously before by mainstream parties. People who are happy and optimistic about their lives and future rarely become extremists.

I find it ironic since your complaint about DEI almost certainly comes from the dreaded trolls you're referencing. I don't actually need a "troll" to tell me I don't want to spend billions of my tax dollars defending Europe when everywhere you look in the US things are falling apart. That's not Russia, it's just reality.