I think the Chelsea owner should be patient with the managers, if he believes that developing the players is simple, why can't he choose to train the players himself? Chelsea has the Premier League youngest squad and wants to win every trophy. If I am not wrong, I don't believe Chelsea has any players above the age of 30 in their current squad, they are only signing young players, and the management expects them to win trophies. In my opinion, this is why Manchester United did not fire Ten Hag, they are afraid of having a bad season like Chelsea.
However, despite how badly Manchester United performed last season but did not fire their coach, management is still pushing to offer Ten Hag a long term contract because they believe he will bring good outcomes to the club. Chelsea management must be patient with their managers, if you believe that the coaches they fired did not produce positive results for the club, I disagree because we saw how Pochettino turned things around at the end of last season, but Todd Boehly believes he is not capable of managing the club.
Whatever is done, of course it takes time to find the best, with Chelsea not being patient, of course they won't find the best if they can't be patient. with Chelsea players who are predominantly young, of course they still have stamina that can be honed to discover their talents, they must be patient in the process to find the best, even though they recruit a new coach it doesn't guarantee they can be the best, especially if they don't can be patient well.
With Manchester United not firing Ten Hag, maybe they still have hope that Ten Hag can still make Manchester United even better in the next season. With Manchester United, Chelsea should be able to look at giving their players and coaches the opportunity to adapt with the aim of finding their best performance.