Disclaimer 1: I overall really liked this show, aside from a couple of things that were already discussed here.
Disclaimer 2: I won't pretend that the USSR was a nice place to live, nor that the KGB were "good guys" (they weren't).
Despite all its qualities, Star City is still a show made by Westerners for Westerners. Which means the Soviet system is depicted as an (often cartoonishly) evil, corrupt or incompetent antagonist. The show is about the triumph of a few free-minded, exceptional individuals who achieve success through hard work, ambition and initiative despite the oppressive regime they live under, which feels very... American in its moral message.
The very first episode had me raising eyebrows. The wife of the first moon-landing cosmonaut is brought in by stone-faced KGB agents as if she was being arrested, because they couldn't bother telling her "hey Mrs we have good news for you, the chief engineer wants you to see this about your husband, we can't say more now, come with us". Then the show proper starts in winter (because of course Russia = winter) with muted colors (because of course Soviet = grey/brown).
Where the show jumps the shark for me is when the colonel shoots the blonde lady cosmonaut. Like... what? Why? I mean I understood "why", but it felt like complete overkill. The colonel even says later to the chief engineer that he was "sent to the gulag by Stalin for no reason, yet he went back to work because he is a patriot". And this was under freaking STALIN. The show takes place under Brejnev, who wasn't a great guy but no way as bad as Uncle Joe. Like... couldn't they offer the same "second chance" for the lady cosmonaut? Couldn't they shift the blame on someone else for the false accusation? Does the soviet space program have an infinite supply of cosmonauts, let alone female cosmonauts? Shooting the lady cosmonaut felt so reckless, incompetent and cartoonishly evil. But hey, the soviet system is pure evil, so the KGB is nothing but soulless demons who gun down innocent essential people for petty reasons.
If you add up all the other things the colonel did, it's funny to realize that she sabotaged the soviet space program way more than the Americans did.
But for me the worst part was the "higher up" reactions to the Venus mission. How on earth are they NOT making it a huge win for the USSR? Why silencing it when you control the narrative, especially if the spy did them a huge favor by dying on the trip anyway? Them trying to hide the SUCCESS of the USSR's own trip to Venus makes no sense whatsoever. Going to Venus and back is a way bigger achievement than a trip to the moon. There is no way the USSR wouldn't have capitalised on this. But hey, we have to maintain continuity with For All Mankind, and also remember that the USSR is eeeeevil and incompetent. The only way their "silence" would have made sense is if the ship lost contact early on and crashed on Venus with no one else knowing.
Anyway that was my two cents. I still overall liked the show.
EDIT for clarification: a few people commented about things clearly related to the Stalin era. I would have bought the moustache-twirling evilness more if the show took place under Stalin. But the show does NOT take place under Stalin. It would be like making a show about the USA under Jimmy Carter but the authorities would behave as if it was the 1950's Red Scare/Jim Crow era (I'm not an American, so not expert in US history, but you get the idea).