What makes some people still doubt Leverkusen is because Leverkusen has only shown their impressive performance this season, they have not yet tested how consistently they can maintain their current performance. In contrast to Bayern Munich, they have been defending champions here for more than a decade, we can already see how consistent they are in maintaining their performance, even though they slipped several times, they were able to recover quickly, which we have not seen from Leverkusen. If they slip, for example, how confident are we that they can recover quickly? no one can answer that with certainty because they have not really been tested as well as we saw with Bayern Munich.
It's actually natural that many people ask that question, because they have a basis for the questions they ask. One of the reasons is as I explained.
I don't really agree with what you said because looking at their track record in the Bundesliga, from the 2017 season to last season they never once got out of the top 6 zone even though there were indeed not too comparable to Bayern but on several occasions they could always be troublesome and only last season they stumbled into the relegation zone first then again started to rally and finished in 6th place.
This is quite the same in the 2021 season where they were in the 3rd position at that time although indeed the difference in the difference was still too far at the end of the season with Bayern but they still proved that they still deserved to be recognized the problem is that we do not know this season whether they are able to make a bigger breakthrough than the 2021 season or not because indeed in terms of quality at this time they are still promising but the season is still very long so we cannot speculate further before they can prove with a good performance until the end of the season.