Chelsea has been changing its coach so many times. It's likely the problem was on the owner of chelsea. The result is far different compared when chelsea was under abramovich's era. All the players seem to lose their strength when it comes into play in the EPL.
Chelsea has no chance anymore to be qualified for UCL. it's become even closer to the relegation zone. i heard that if pochettino has been reaching the final aggrement with chelsea. He was not so bad as a coach. Pochettino was able to make totenham almost winning EPL but it was not winning due to the leicester city has more points at the end of season compared with totenham. I can hope only if there will be progress in chelsea. Chelsea has been changing its manager a few times and so far there's no improvement that happened with the club.
There's no improvements happened with the club when chelsea under lampard as caretaker until the end of season.
Under Todd Boehly era, Chelsea have changed two manager without one season ended from Thomas Tuchel, Graham Potter and the last Frank Lampard will extended until the end this season although have have loss in five games in a row all competition from Champion League until Primer League. I think underperformance from Chelsea started when Roman Abramovich have left Chelsea as the owner and Todd Boehly failure how the success era building from previous owner, indeed Todd Boehly have spent much money in transfer and recruit stars player seems not enough bring Chelsea placed on top standing position.