I agree with you that Chelsea are currently waiting for the moment when the club above them slips repeatedly, and when that happens they will take advantage of it to be able to shift them in the standings.
Honestly I am also surprised by the development that Chelsea can show, because last season they were still bad and I didn't think they would recover this quickly, yes even though this is just the beginning and they could lose consistency, but still what they have shown at least until now is something very good. they can compete again at the top of the standings which they have not done in the last few seasons.
Just recently, when Maresca came to Chelsea, he said that he had too little time to change this team, and to achieve great results they will need more time, but apparently the team is progressing much faster than he thought. Now Chelsea have the best attack in the Premier League, but between them and Liverpool 7 points is a lot and this is only a third of the season, and Arsenal and City will not let them go so easily.
I also didn't think that Chelsea would improve this drastically and maybe it's not just me. Nicholas Jackson, who was not very visible last season, has now become a goal scoring machine, as well as Cole Palmer, who looks increasingly mature and more stable. If they only target the top 4, it is very likely that they can achieve it. If it's the Premier League champions, it seems the chances are still quite tough because Liverpool is so strong this season and it still remains to be seen how long Chelsea can be consistent.