I think Smash would have been the perfect game to break that trend since Smash is a giant celebration of gaming and a complete package, not just mindless fan-service thrown together. For the lack of better words, it's the Avengers Infinity Wars/Endgame of gaming with the amount of crossover, detail, and love. Something you see when you see Sakurai talk about Smash in his presentation like with Terry. Max actually says it best when he said that the one thing he loved about Smash is that Sakurai gives a damn.
To be sure, I am not saying Sekiro didn't deserve to win. I just hate the mindset that Smash shouldn't win because 'meh, fighting game' instead of simply saying Sekiro was better.
Problem is, I don't even think anyone can compare Sekiro and Smash, they are too different to decide which one should have been awarded.
However, at the end, the press will always give more importance to certain genres than others, no matter how good the game is.