He is probably content for now. I think you have been very determined, in trying to make this same point over and over, to twist the words of many. He may well be happy now, most posters have envisioned, by sheer logic, that he will not REMAIN happy if his situation remains the same. The situation being he starts one game then sits out the next as a rule. What if we play a big European game, and then Liverpool or City in the next? He will surely not be 'happy' to not start the game, simply because it isn't 'his turn'. Especially if he happened to put in an excellent performance in his last start.
The situation seems fine for now, but it is obviously not tenable in the longer term. If Martial and Rashford are to become the players we want them to, neither are substitute level players. You don't have £100m players in their prime on the bench. And we shouldn't want that either.