However, wealthy investors are usually not immediately interested in teams with very poor performance. Therefore, if an investor wants to invest in one or two teams other than Bayern Munich, they will likely examine the team's structure and overall management more closely to avoid investing in the wrong direction. Therefore, the lack of wealthy investors interested in teams other than Bayern Munich in the Bundesliga is also a reason why other teams have been unable to advance and dominate the Bundesliga competition as seen this season and in previous seasons.
Bayern Munich is a richest and most successful club in Germany and Bundesliga in history and latest decades too. With abundant finance as a richest club in Germany, Bayern Munich have huge advantages with best transfer budget and biggest budget for player salary. The domination of Bayern Munich in the league comes from many factors which don't own by other clubs in Bundesliga, and that's main reason why other clubs can not beat Bayern Munich in many seasons.
That's not how it works in the Bundesliga. It is very different to other countries. Generally, investments are possible, but under very strict guidelines. Also, teams can't be owned so they also can't be sold to some rich clown in the middle east. Thankfully there are rules in place to prevent things like this to happen and secure the integrity of fair play. It's a shame that other countrees don't care about this.
Bundesliga title is almost for Bayern Munich as with 9 points more than Dortmund, it's really difficult for Dortmund to catch Bayern Munich and win a title. In more than ten latest years, Dortmund failed against Bayern Munich in most seasons and with big difference now, I don't imagine any scenario how Dortmund can beat Bayern Munich in the title competition this season.
Behind them, there are five clubs with not big point differences and all these five clubs are fighting for two last positions in top four of Bundesliga. Even a second position of Dortmund can be taken over by those five clubs as Dortmund still don't have enough big and safe difference against these clubs behind.