Seems like the author has run out of motivation, so the artist is carrying the team by drawing full chapters of every minor event.
This chapter was a single dungeon rush from the holy knights (which also was happening last chapter)... and after being repelled this time they released the MC's next waifu (who was already revealed at the end of last chapter).
Hopefully the new waifu inspires the author to actually build a storyline again. Otherwise I expect this manga will produce several more chapters with zero substance before finally sputtering out.
You have things backwards and very wrong. The author wrote the novels, not the manga. More specifically, the initial WN, the LN, then the
R18 version of the WN, which is better than both. The artist in question - whom you seem to credit with "carrying" this series - has radically altered it in a very bad fashion. This adaption is beyond inferior to what I linked, to an amazing degree. I'm reading this adaption simply to kill time, and I'm at least grateful since it introduced me to the rather excellent, if insane novel. Still, you're blaming the wrong person.
If I had to find any fault with the author, it is 3rd person perspective chapters, where people tend to drone on too much, which gets old. As for the manga itself, I probably wouldn't have so much complaints (though it wouldn't be noteworthy either), if I didn't know the source material.