If you master in opening and endgame then Bullet is easy for you.
I agree with the first part of this but not the second. By the time an endgame is reached, if an endgame is reached, there is little time left.
In a online tournament. Opening takes 4-5 seconds and capturing takes 15-20 seconds. And this is all about endgame. (If you analyse GM's game you may notice that they get 90+ accuracy in each game.)
Without time control?
Yes. Chess does not inherently include time controls; we just have them to 1) Challenge people and 2) prevent people from taking too long.