As far as 40K is concerned I think it mostly comes down to the main faction of the franchise being a hyper religious, fascist nightmare and GW shitting the bed when it comes to presenting any real alternatives. Every faction is at least a little evil or extremely selfish. This leads to the very fucking evil Imperium coming of as "one of many" or "not THAT bad compared to Chaos".
However, I don't think this was the result of intentionally propping up fascists as cool and good and more the result of corporate ghouls not getting satire and as a result removing those elements from the narrative until we have arrived at the current point in time. Where we are told by GW that the Imperium is a fascist shitshow and is surviving DESPITE being so shitty. While pretty much all of the novels are portraying the Imperium as surviving BECAUSE they are so shitty. If any of the other factions were definitely good this wouldn't be an issue.

Pretty funny that factions in Fallout were supposed to be exaggerated parodies but yet we still have many in the fanbase unironically supporting the Enclave, Legion and the shit that Liberty Prime spews lol.

I've definitely noticed it with grand strategy games, take this with a grain of salt but I assume that it is because these kind of games let the players live their political fantasies, which I guess it's more appealing to people who want a different kind of society than the one they live under IRL. This is all just speculation though.

I personally like these games precisely because of that reason, I like building up socialist countries in Victoria 3 because that's currently the only way for me to "have a taste" of socialism, even when it's just a bunch of pixels on screen.

So the given examples tend to involve heavy critiques of nationalism and fascism but fascists think that shit’s cool. Liberty prime from fallout is a beloved meme for fascists but also is literally talking about how they’d rather be dead than communist in a post nuclear hellscape that once was the capital of a superpower at the end of a game where the plot revolves around getting access to clean water. Caesar from new vegas is a fascist depicted as a loser who couldn’t cut it in the new California republic so he turned to banditry and pretending to be a Roman, but he’s misogynistic and kills a bunch of people and that’s how fascists want to be seen.

For civ, it’s a game about colonialism, but also all sorts of cultures are treated as special and as having their own things of value.

Most of those are satires of fascists meant to point out how stupid they are, but the fascists are too fucking stupid to ever realize it.

Games Workshop (warhammer and warhammer 40k) even put out a short comic where the space marine protagonist kills a bunch of literal nazis and tells them they aren’t welcome anywhere to get the point across and the irl nazis only barely caught on

EFT, escape from Tarkov. Its a detailed gun modification and shooter game. It has a lot of gun fantasy and mercenary like Wagner fantasy with a lot of looting. Its a right extremist heaven.

But it is also very delusional about its hardcore and realism. The gun shooting is one of the worst in fps gaming, intentionally designed to even the field for bad fps players bc the Boss of the company sucks at fps games. Being delusional attracts people

And its a russian game which attracts far left people. With a lot of AKs.

Wasteland 3 has an amusing sub-plot involving some fanatics that have revived Reagan as an AI.

There's also a community of sentient robots that have liberated themselves from humans and have collectivised everything.

You can download (kidnap) AI Reagan and hand him into the custody of the communist robots where they promise to deprogram him.