Well, there are five reasons why the Bundesliga isn't so competitive.
1. domination of bayern munich.
if there is a party responsible for the supremacy of Bayern Munich itself who is able to answer it. because they have quality players, squad depth, top managers to die hard fans. "The Bavarians have it all"
2. too many young players.
however talented, they are still in the learning stage and still need a lot of experience.
3. inconsistent appearance.
Apart from having the qualities of a champion, Bayern Munich's dominance is also much helped by inconsistent performances by its competitors.
4. Profitable business.
many clubs in the Bundesliga sell important players, Bundesliga clubs are famous for supplying their great young players throughout the European leagues.
5. the 50+1 rule, a rule that requires 51% ownership to be owned by club members. while the remaining 49% shares are the maximum limit for external investors.
I think point 5 can answer from your post. that's why the Bundesliga is difficult to become a more competitive league.
The first four points are rather the choice of the clubs - nothing prevents them from building their business model differently and developing towards better sporting results. Bayern cannot take away all Bundesliga revenues and all 4 Champions League berths. As for the 5th point, I don’t understand why no one has guessed to get around it yet? Why can't the conditional Abramovich become a member of the club and own its shares as a member of the club (and the rest of the shares will be acquired through some kind of trust or other investors)?