Yeah, but you're a conformist. I guess you'd be okay with seeing the same champion for the next 20 years. Did you also like the Super League? Because it essentially followed the same line of thought you just demonstrated.
If by conformist you mean that I'd rather see Bayern win another 5, before a billboard like Leipzig win their first, then I guess I am one. I'm not sure what you're referring to with your ESL comment though.
There are two things holding back potential challengers:
a) incompetence
b) a lack of money
Maybe you can make some kind of management seminar mandatory for licensing, but in the end clubs will have to overcome leadership and club culture problems themselves, no one else can help them there.
When it comes to money sustained growth is the only way. You keep going on about 50+1 again and again, but please, do actually take a look at the real world. Bundesliga has clubs that effectively operate outside of the bounds of the 50+1 rule. Are they challenging Bayern (beyond Leipzig having Nagelsmann for a few years)? Look at the rest of Europe. No one else has a 50+1 rule, they can all do what according to you will make Bundesliga great again. How many clubs are out there who grew from the size of your typical Bundesliga midtable club to a team that could reasonably challenge Bayern. Then subtract the clubs used for sports washing and then feel free to list the numerous clubs among the hundreds of candidates in Europe who took the path you are suggesting. One time payments are just that, you can buy a couple of good players once and by the next cycle the money and the players are gone.
The only way out of this is the one Dortmund took:
step 1: be a reasonably big club in the first place
step 2: do good work for a sustained period of time
step 3: make CL reliably enough you can actually calculate with the increased income without risking bankruptcy
step 4: gain international exposure, keep star players (for longer), create a team that is used to European competitions and doesn't choke on its inexperience
This is where the plastic clubs come in, because they keep cock blocking clubs like Gladbach or (recently) Frankfurt from reliably playing in Europe, while they themselves have absolutely no potential to grow into something that could challenge Bayern. And part of the reason why can do so effectively is that while other clubs get into deep trouble when they miss their targets they can just call up daddy's marketing department. You can act a lot more freely with that kind of safety net.
Subtract the plastics from the equation and Gladbach, from Favre onwards, probably make top four like 80% of the time. They would be a completely different club by now. Maybe not challenging Bayern, but a serious T2 team in the CL.
Even Dortmund, not that anyone has to feel sorry for them, will be set back a year or two at least by missing out on top four to Wolfsburg and Leipzig.