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.
But there is also a difference when the gap is big because all other teams are weak or whether the gap is big because one team is playing on an unbelievably high level. PSG has this huge advantage mostly because Ajax Amsterdan isn't able to sort out their issues because otherwise the gap would probably not be as big as it is now. But in the Bundesliga it is now that Bayern Munich finally has a competitor who wins game after game with hardly any interruptions of their winning streaks.
Now overall we are having few changes in all leagues with few are losing their quality like we have in France, but many others are doing impressive which is surely good like English Premier League is always challenging, and they have good teams at the top now Bundesliga after few years having good improvement and many teams are fighting hard for the top slots which is bringing good improvement and it's good and Bayern Munich is surely facing challenge and in this season their defence is also not good as they have in last few years like conceding 5 goals in one match huge problem.
Teams like Bayer Leverkusen and RB Leipzig are surely on improvement because they are doing good work for their squad and also maintaining good performance which is now giving them good reward in Bundesliga and UEFA as well.