After Leverkusen won the trophy last season, several teams such as RB Leipzig also seemed motivated to work harder to join the hunt for the title this season. Do not forget Frankfurt is also a candidate that needs to be watched out for. As a result Bayern Munich who must win the Bundesliga trophy must face 3 strong teams. Last season only Leverkusen but now Frankfurt and RB Leipzig are also obstacles.
I think it is not because of the success of Leverkusen in the last season. All teams will try to be better in each season, they must be always motivated to win the trophy. In Bundesliga, we have few strong candidates recently, they are Bayern Munich, Leverkusen, Dortmund, and RB Leipzig. I think only these teams who will compete for the trophy until the end of the season. Meanwhile for Frankfurt or Freiburg, they usually start to lose their consistency in the middle of the season.
Bayern Munich doesn't only focus on the big teams only. Sometimes, the small teams become the obstacle because they play with a more defensive tactic. When a team plays very defensive, it will be harder to score goals. So, Bayern Munich must be careful when they play against small teams, too. It also can be a bad result when they get a draw.