Hoping to compete for the title against Bayern Munich may be far from ideal, but being able to compete in the top three at the end of the season is much better. There have been many changes at Leverkusen, with several key players leaving, and Ten Hag's arrival as head coach doesn't guarantee the team's progress. Dortmund is also experiencing the same problem and now the team's condition is not much better so hoping for Dortmund or Leverkusen to break Bayern Munich's dominance has no chance at all because Bayern Munich's strength is much stronger with the arrival of a number of new players.
Dortmund and Leverkusen won't pose a serious threat to Bayern Munich this season, as neither team is yet on par with Bayern Munich in terms of strength. However, if we look at the details, Dortmund might be better than Leverkusen this season, although Dortmund won't be able to break Bayern Munich's dominance this season, as Munich remains quite solid with the depth of their squad. I wouldn't expect anything less from Leverkusen or Dortmund this season, as Munich will never neglect any opportunity to win this season.
It would take a miracle for Leverkusen or Dortmund to compete with Muenchen this season, as without a miracle, it would be difficult to compete. It's impossible for Muenchen to play poorly all season, considering the squad Muenchen currently has is already very good, and Kompany is also more confident after his successful first season.
As you said, both Leverkusen and Dortmund haven't shown significant improvement, especially Leverkusen, who lost several players and whose management also gambled on hiring coach Ten Hag, who clearly failed miserably at Manchester United. Looking at the squads of each team in the Bundesliga this season, only Muenchen is predicted to be consistent until the end of the season.