For me I think Street Fighter (and most other fighting games) avoid all the most frustrating parts of PvP.

No teammates to worry about. Whether they're bad players that need to be carried, or trolls, or just some raging screecher. They're annoying more often than not in team based games, and even when they're not usually they're just... non-entities quietly playing the game. There's little to no social engagement in modern team based multiplayer, so what's the point?
Some people might find the lack of a team frustrating as that means there's no one else to vent at or assign blame for a loss to other than yourself, but those people can piss off and keep playing their MOBAs. They're just making the experience worse and I'm glad to have something keeping them away.

Very well balanced. While I'm sure there are other balanced fighting games out there this is more specific to SF6. Capcom has done an incredible job balancing the cast. People like to talk about who's top tier and complain about matchups they don't like, but looking at the overall win rates online you can see that the best v worst character is only a 3% spread. Some individual character matchups are pretty wildly skewed, but I think that's fine.

Both players have perfect knowledge. This is a big one, imo. Nothing is hidden from either player. You know where the other person is at all times, exactly how much health you both have, and exactly what resources. Losing to something you were not aware of is one of the worst feelings in any game, and most fighting games avoid it entirely.