After winning the treble this season, Manchester City may be the best team in the world. However, if they do not spend enough money on acquiring new players, the void left by the previous ones will not be filled, and they will struggle in the coming season. Those players who are about to leave the club should be known to the club by now, and planning for their replacement should be underway. Manchester City have spent a lot of money to establish such a strong team, and if they want to keep it, they'll have to spend money to bring in new players as the old ones are leaving.
Thish is true. There's still a lot of work for Manchester City to do. Players like Gundugan would be leaving and he should be replaced. Benardo Silva is also a player that may also be leaving. Manchester City needs a right back too that can back up Walker.
Then they need wingers, on both sides of the wings. Grealish has been okay this season but he needs to be better than okay. Benardo Silva is not a natural winger. Mahrez might leave so he needs a replacement.
As long as Pep is their manager I have no doubt that they will get the right players for the future. They have the money and the brains to keep their squad strong at all times.