Bayer Leverkusen provides a very long distance in points between second and first place. For Bayern Munich, this will provide encouragement to catch up on the points they are left behind, and of course Bayern Munich has an opponent that must be immediately defeated in order to take first place again. As long as Bayern Leverkusen remains consistent and can work well as a team, it will be easy for Bayer Leverkusen to win the Bundesliga this season.
If that is what you describe as a very long distance, then I think you have never really seen a team leaving the other teams behind by a very long distance.
Maybe you should have a look at the Netherlands domestic league to see what that really means. PSV Eindhoven is leading the table by 10 points with a perfect record of all games won and I think it is ok to say that this is a long distance because it will probably continue like that.
But being ahead of Bayern Munich with 4 points only is nothing when you consider that Bayern Munich also played one game less than Bayer Leverkusen. This advantage is almost meaningless and not "a long distance".
We have distance like this in many leagues as this can happen to any team like we have in past by Bayern Munich and then PSG and in last year we have Napoli which was once having 17 points difference and then now in current season mostly teams are doing good competitive performance but as described PSV is playing completely in another level which is giving them good edge just after 16 rounds.
Currently, no doubt having this distance here in Bundesliga between these two teams is nothing and Bayern Munich is also having good ability to fight back without any problem but right now as we have consistency in Bayer Leverkusen is also impressive and things have never been challenging hopefully, we will have good end of this season.