Smash Ultimate is going to win for sure. The only game that can kinda go toe-to-toe with it is MK11, but I'm pretty sure Smash has more copies sold, more players, more viewership online, and honestly the game is an achievement considering it was able to bring back every previous fighter including guests like Snake. Pretty sure it broke records by becoming the fastest selling Nintendo game also, so I think all those things mean Smash is going to have more voters and the people behind-the-scenes at TGA that make the final deciding factor have more of a reason to see Smash as "the best FG" on the line-up.
MK11 has the best visuals out of any fighting game if we are ignoring animation and talking about realistic graphics only (kinda unfair to compare to anime FGs, for an example), but I don't think that's enough for MK11 to take the win. You can argue that Smash "Isn't a real FG" so MK11 would be the winner, but 1) that's dumb, and 2) If they didn't see Smash as a real FG it wouldn't be on the list.
Dead or Alive 6, Jump Force, and Samurai Shodown are niche to win.
Seriously, Smash is probably bigger than every other nominated FG on this list combined.