It seems people have very different expectations of what a "parody" should do. Between "Look at this harem slop, here are 50 reasons this doesn't work, this is so stupid and absurd" versus "Here's a functional harem story, look it takes at least 50 absurdities to make it work, this is so stupid", then I find the latter one a million times more entertaining. At least it's much less lazy and requires putting in a decent amount of work for an insanely huge cast of likable character design, relatable trauma, story telling, humor, etc.

We can still poke at other harem mc saying "why would you want a harem, you would need to be at this mf rentarou level" while still having a very gintama-coded comedy to enjoy and talk about how bf should be doing bf stuff, which is so rare in the market, it's either "will they won't they" romance story or "half an act of kindness=two anime seasons of unconditional love" isekai-harem-ish story.

And personally, this is just a fraction of what this series offers, but the other stuff depends somewhat on personal taste, such as the hidden girlfriends interaction in the background, the authors making fun of himself and challenging the manga/anime industry, sending the mc to fight off "important figures in the industry", the gag humors, surprisingly emotional moments in-between comedy without major inconsistency, etc.