I will disagree with you that Manchester United's performance was poor last season, if you said Manchester's United performance was poor at the beginning of last season I would agree with you. Last season was one of Manchester United's best seasons and United ended up winning a trophy. Chelsea is the only club that has had a poor performance at the beginning of last season throughout.
Obviously the last season, Manchester United wasn't that poor because they can still finish in 4th position and won Carabao Cup. But it was just a fluke, they have a same squad and same coach, but this season, they're perform really bad.
Chelsea had a terrible result in the last season, this season it might be Manchester United' turns.
This cannot be controlled and yes, Manchester is a mediocre team this season after recording some good things last season. Together with Erik Ten Hag, Manchester United is a very chaotic team and everyone always criticizes his performance this season, which is considered a failure compared to what he did last season. I don't know how long this will last and what is clear is that at the end of this season there must be a discussion from Manchester United management about retaining Erik Ten Hag or replacing him with a new coach.
There is no difference between Chelsea and Manchester United this season and both have had bad results. But at least Chelsea is still a little better even though they are quite late. The possibility of swapping positions for these two teams is still possible and Chelsea is also getting closer to overtaking Manchester United in the standings and that will be their turning point this season.