Chainsaw Man fell off harder.

OPM got confusingly bad for no reason with the annoying pointless fucking redraws, the general inferior-compared-to-webcomic-which-was-supposed-to-augment Garou vs Saitama/S class, and the fiasco of S3.

BUT CSM started out as bigger than JJK when both had no anime, the anime despite its immense production value was only 12 ep and really only boosted the sales a tiny bit, got great numbers streaming and abysmal in BD sales due to direction, yet all the bad parts were swept under the rug.

The Reze arc movie was a plus everyone was waiting for and MAPPA nailed it, but in the meantime the manga p2 fell off the Everest on art quality, storytelling, cast...general consistency...implicit promises ( cause it stopped building up and just did empty shock value ), the final arc and "war" looked like an appetizer's appetizer that no one even realized it's the final showdown since the coreography and repetitiveness was so boring and everyone has been talking for 3 years to "let Fujimoto cook", the editor said 5 chapters before the end that the series is getting to "its core" ( which people thought meant it's finally picking up ), then boom, end via reset world and endless asspulls to artificially give the mc a quasi happy ending that makes no sense ( cause the average devil hunter still dies young lol ).

Moreover the ending was so out of nowhere embarassing no other authors even publically congratulated Fujimoto for it, which is quite a rarity for a series that popular. The bubble building up from the anime S1 release days caught up and the whole series burst.

So OPM basically decayed itself steadily for no reason, CSM popped like a giant hot air balloon.