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.
When you have the right coach with a very good philosophy in place then you are bound to experience rapid success in a very short time, and that is what exactly is going on at Chelsea FC, they have a very young team with so many dedicated players who are ready to learn and developed into world class players with the help of the manager and I believe they can achieve more than what they have achieved this season and beyond by being consistent and putting more hard work and also aiming higher. For me, I have so much confidence in the coach and I think this Chelsea team might replicate the feat of the Chelsea team that last won the champions league under Thomas Tuchel.