I think excercise is relative not an absolute. Some people become masters after little excercise (see Capablanca) others after a lot of excercise (see Alekhine that became champion after studying a lot the style of Capablanca and profitting of the self confidence of the cuban that didn't take seriously the challenge. But Capablanca learned the lesson and was ready for the return match. But Alekhine was very able to refute the revenge. I've never accepted the behaviour of Alekhine). So for me one only thing is necessary to become a master: to capture the essence of the game. Something misteryous must happen in your mind and soul so that you capture the essence of the game. If you get that you get everything. After that excercise is useful to remain fresh
Can you become really a master through exercise?
Why there so many players on Chess.com who have played thousands of games and still have a rating around 1200 or even lower?