I would say that the Bundesliga is the third strongest league in Europe (and therefore probably in the world) after the english premier league and the spanish primera division. Of course it was kind of boring in regards to who will win the Bundesliga title in the last 10 years because it was Bayern Munich all the time in those years but that definitely does not mean that it is the worst league in europe.
You can also not blame Bayern for their success. They don't have any debts, like Barcelona. They don't have a sheikh or oligarch investor like ManCity or PSG and still they are among the favorites for the Champions League title. Bayern is just doing an amazing job in regards to the management of the club.