Title, I'm a leftist but after reading some things on lemmygrad and here it seems I might have been lied to all my life. I have talked with some people from Cuba and Venezuela (expats) that support the west narrative about poverty and mismanagement. I "believe" that Russia is attacking Ukraine for selfish reasons and that China censors access to foreign information using the Great Firewall, please prove me wrong. Furthermore, it ultimately depends who do you want to believe or there are hard facts from reputable sources that are simply a hidden by the mass media?
EDIT: Thanks everyone for your very civil responses. I'll answer as many as I can!
I'm gonna go straight for your last point and address the "working out pretty well" bit - there's a really good Yellow Parenti clip (if you're a new lefty yellow parenti is a series of lectures from a famous and extremely rad Marxist academic named Michael Parenti) that talks about judging Marxist revolutions against why things aren't perfect the day after the revolution. Essentially, things like this take time and they're going to be messy.
China has a lot of reasons for implementing their Great Firewall: Outside propaganda attacks from adversaries, domestic capital-holders desiring to increase access to capitalist propaganda to steer state policy in a more capital friendly direction, radicalized individuals becoming more so because of maliciously crafted outside media, etc. Parenti's addressing this is "civil liberties for the fascists", which is a bit reductive, but "unfettered global access for everyone" falls in the same bucket: it's not something China is obligated to provide if it would adversely impact their ultimate goals of bringing quality of life to their people and increasing the dominance of socialism over capitalism.
Would it be nice? Yeah totally, I wish they could have what we do information-access wise. But the Chinese state believes that it would detrimentally impact their socialist project and I'm personally inclined to agree but they probably know their people better than I do anyways. Bringing it back to "working out pretty well", all we can judge them against is how well their socialist project is doing as a whole, and while there are a number of issues ranging from mild to serious, they have overseen a raise in life expectancy, literacy, health, education, access to quality medical care, and access to healthy nutrition that is basically unrivaled except by other socialist projects. Trying to judge this one policy in a vacuum would be hard even for native Chinese citizens, all I'm personally inclined to weigh in on is to say "Well, it looks like their chud brainworms per capita are a lot lower than ours so I guess it's going alright".
Thanks for putting in the effort I was too lazy to, I appreciate it :order-of-lenin: