I applaud you for acknowledging the benefits of socialism even though it sounds like you disagree with it overall.

I'd encourage you, though, to think more about what "authoritarian" actually means. All states claim authority to use violence. The only limits states acknowledge on how much violence they can use are the limits they agree to (and therefore can abandon at their convenience). All states sharply respond to certain types of dissent -- certainly violent dissent, almost always dissent that (the state claims) is associated with a foreign state, and often even peaceful dissent. This applies to any liberal democracy you can name. Look at how many peaceful protesters the U.S. brutalized in 2020, look at the recent U.K. ruling on sentences for peaceful protesters blocking roads, look at how Germany preemptively bans even discussion of Nazism.

So when Cuba arrests dissenters who are backed by an extremely hostile foreign power, is that any different from what the U.S. would do? When the USSR arrested nationalist dissenters who sympathized with Nazis, is that any different than what Germany does? What actually makes these "authoritarian" countries different from the "good" ones, apart from having the audacity to reject capitalism?