Give a possible way that can make what you want to happen in the Buli.
Bayern hardly lose its best player while by this summer Bellingham and Nkunku possibly Gvadiol are leaving the 2 teams closest to giving Bayern a challenge. So how do you expect Dortmund and Leipzig to compete next season. City has Gundogan Akanji Haaland and KdB from the Bundesliga. Possibly Dortmund could have won the league this season with Haaland instead of Modeste/Haller.
EPL is outspending the rest of Europe using some of these oil money you hate. Chelsea is spending more than 3 leagues combined and you think there is a way around it. The only reason Madrid and Barca have remained competitive is because they take an unfair share of the TV money
In Europe the clubs that can match Bayern are the traditional clubs which were already rich by the 90s or oligarch clubs which I suppose you despise
There are 2 ways to make the German league more competitive
1 Strengthening others clubs to the level of Bayern. By taking Oligarch money which you preach against
2. To weaken Bayern to the level of the teams below them and become another Belgian league which you enjoy the competition?
No club can build organically to overtake Bayern as it is. Just like Chelsea Man City (who have won 7 of the last 9 EPL titles) needed oligarch funds to move from midtable teams. Best you can do is to get a great group of players and a good coach. who will be taken apart by the next summer.
I've been thinking a lot about this lately. Although I'm principally against 50 + 1 and think it is to blame for Bayern's dominance since it makes it impossible to catch up to them economically, I see the arguments for it as well. It really sucks that you can't root for your favorite players in world football anymore without a bad aftertaste since they play for a club that's backed by a regime with questionable ethics to say the least.
But there's no easy path out of it for the league. The obvious solution would be to enable Bundesliga clubs to compete financially but this is impossible with 50 + 1 in place. Not even Bayern can do that because most of these clubs don't have to be profitable. Still it important to further improve on the commercial side of football, like e. g. Frankfurt is currently doing. But this could also mean a new scheduling of games, etc. Fans should be made aware that this is a bitter pill they have to swallow if the league shall not become completely irrelevant.
Second, I feel that this insane transfer fee inflation we've been witnessing in the last 5 - 10 years can also be a chance since prices of other markets aren't growing at the same rate. For instance, imagine you plan to build a new training facility for the youth teams, employ new coaches etc. Maybe such a project has doubled its necessary expenditures over the last 10 years but at the same time the prices at which you can sell your greatest prospect has increased thrice. This really shouldn't be underrated, especially since some top clubs such as Bayern or until recently Liverpool signed so many players on a free transfer as well. It's absolutely insane that for instance Chelsea bought Hazard for €100+m when he only had one year left on his contract.
I believe this is the strategy most clubs outside the EPL should pursue. Don't partake in the insanity and price inflation but instead capitalize by investing the money long term. It should be about optimizing the development of young talents. If you think it through, there are 20 EPL clubs plus PSG, Bayern, Madrid, Barca and maybe Juventus. That makes roughly 25 clubs able to pay astronomical salaries. Assuming all of them pay around 20 well earning players, that means roughly 500 high paid jobs in European football. If the other leagues produce so much talent that the amount of top players exceeds their demand, smaller clubs will be able to retain some very good players again. And if they don't buy them back for crazy sums and salaries, the insane money the top clubs spend will be redistributed down the pyramid again.
That's the chance I see for football right now. We're already beginning to witness it in a few positions. Kvarathskelia for instance is an insane talent but most top clubs have no vacancies in his position. Sancho was a similar case with only United being interested in him despite his great performances. Of course clubs will make room for such players but that also means somebody plays and has to find a new club.
So in essence, take the money from the top clubs, invest it wisely in persisting assets such as knowldege, processes and infrastructure that generate revenues and player quality sustainably, flood the market with top players and stop doing crazy things to enforce short term success - leave that to the clubs that have money to waste anway. A bit similar to the idea that when your country doesn't have natural resources, your natural resource has to be the brains of your citizens/education.