Yaya is a carbon copy of Mourinho, in terms of he can guarantee you success short term because he is so immensely talented but he also alienates his own team after a while because of his selfishness.
Football is a team sport and the only way you can keep harmony and spirit in a team in the long term is if everybody works together and works for each other. When one person is in it for personal glory or isn't putting in the same effort as everybody else it creates resentment and a lack of trust in the group which divides it (e.g. Ronaldo refusing to pass to Bale). Mancini lost his job because he continued to pick Yaya who clearly wasn't giving his 100% effort in his final season and it's looking very much like Pellegrini is going to lose his job because of the very same issue.
At the end of the day you pick a team based on who is working the hardest. If the most talented players aren't getting picked then they need to work harder to get into the team and justify their selection, if they're not prepared to work as hard as others in the team then open the door and fuck them off.
Football is a team sport and the only way you can keep harmony and spirit in a team in the long term is if everybody works together and works for each other. When one person is in it for personal glory or isn't putting in the same effort as everybody else it creates resentment and a lack of trust in the group which divides it (e.g. Ronaldo refusing to pass to Bale). Mancini lost his job because he continued to pick Yaya who clearly wasn't giving his 100% effort in his final season and it's looking very much like Pellegrini is going to lose his job because of the very same issue.
At the end of the day you pick a team based on who is working the hardest. If the most talented players aren't getting picked then they need to work harder to get into the team and justify their selection, if they're not prepared to work as hard as others in the team then open the door and fuck them off.