Of course, this is only an assumption on paper, which means that clubs that have already qualified for the round of 16 have the same opportunities and opportunities to advance to the quarter finals or further. I agree with you, many surprises can happen and sometimes when we are too confident in one of the teams, and are favorites, we end up being eliminated early.
The knockout rounds which will start in february next year will give the 16 teams time to focus on their respective domestic leagues. City, Bayern and Madrid, as the most favored teams in the UCL, are losing the top of the standings at domestic level at the moment. however in my opinion, this does not necessarily eliminate their status at UCL.
The knockout round is often the round where surprises occur. Some teams that may experience difficulties in their domestic leagues can appear very strong in the UCL and vice versa.
Yes, I agree that City, Bayern and Madrid as top teams definitely have the quality and experience of competing in the UCL.
However, seeing the clubs that have already qualified for the round of 16 with the same opportunity to progress further gives the feel of a fair and competitive competition. All teams have a chance and should be respected as serious contenders.