I didn’t disable anything on my PC. My roommate had the same problem and he’s pretty tech illiterate, so I’m sure he didn’t disable anything either.
Why wouldn’t you think Starfield would be playable on Linux? The list of incompatible games has grown very small. I cant imagine they would have kernel anticheat on a single player game from a company that had traditionally embraced mods. That seems to go against Bethesda’s whole attitude. And nowadays kernel anti cheat is pretty much the only thing stopping people from playing any game on Linux.