Well, they had an opportunity to make this upcoming season much better but they decided to let it slide by kicking Mauricio Pochettino out, that man took them to the Europa League spot after several errors by previous coaches and if not that Manchester United defeated City to win the FA Cup, Chelsea would've played in Europa League instead of Conference League, but then how did the board pay him back, by cutting ties with him when his bond with players on an off the team became strong. Enzo Maresca might encounter lots of difficulties and things might be worst than other coaches, not leaving behind the fact that he could have a serious confusion in selecting his best XI due to bulky squad depth. As for changing Maresca, it won't come like a surprise given that Todd Boehly lack patience and won't hesitate to look for another option if Maresca doesn't miss his expectations.
Chelsea was to quick to be sacking Mauricio Pochettino everyone deserves a chance to improve I can count how many coaches Chelsea have sacked within two seasons and if they continue like this people won't really have enough time for their strategy to actually work, but all Chelsea care about is instant result and for them to get exactly what they desire they will need to give their coaches more time to be able to establish what ever plan they have an not rush and expect to get results. Winning Europa was not enough for them. If not they would have even appreciated him at least winning a title for them but they want Chelsea to be equal with Manchester City and it won't be possible. They can not be on the same level with Manchester City. And even Manchester United winning the fa cup was all luck to me. Look at what happened to Manchester United during the preseason game with Liverpool they did not even stand a chance against them that is Liverpool for you. Enzo Maresca Will also try is best and and if they don't get results am sure Chelsea will fire him also but this season am sure nothing will come out of Chelsea.
Honestly, the way Chelsea have been sacking coaches, that's why they are not getting reasonable improvement from those coaches. If they had given them more time, it may have led to great improvement for Chelsea. As for Pochettino, I was not expecting that Chelsea would sack him so quickly like that, with the way he was trying his best. If Arsenal, which have improved under Arteta, now have the chances Arsenal has given him, I don't know why Chelsea will not be that patient with Pochettino. Any teams that sack coaches anyhow will find it very hard to see what they aim to achieve. Many coaches that Chelsea have brought and sacked were better managers in the teams they were in before,but the time Chelsea is not giving them is what is causing them not to achieve Chelsea's aims.