I feel like too many people reading this are only reading it for the slice of life chapters and ignoring the entire premise of the series lol I mean sure, the bread and butter of the series has been the slice of life shit covering their daily married life, but there are literally thousands of slice of life manga that do the same exact thing, this series wouldn't have last this long if it didn't have the overarching plot as its hook, being "this random cute girl saved MC from getting hit by a truck by getting hit herself and surviving without much damage, so I proposed to her and she said yes". I mean even the first chapter had been hinting at something being different about her considering she took the full force of a truck that would have killed a normal person.
The early chapters were throwing hints at her immortality and regenerative abilities far more often than the recent chapters, but its still always been the underlying main story. Chitose and Tokiko were introduced based on their relationship with Tsukasa and how they knew her secret, the bath house girls were obligatory MC childhood friends, but his students even had some ties to Tsukasa and the main plot because of Kaguya and whatever her secret is. For the most part its always had the main plot in mind, and if anything everyone is getting mad at the fact that the filler chapters finally stopped coming and it began focusing on the actual plot and literally the only mystery the series really has lol
Plus its already been confirmed that the series has been going into its endgame and will be ending soon, though we haven't gotten an actual date or window, but its pretty clear to see, so why wouldn't Hata start resolving the one hook the series has? Hell, he was originally planning to end the series way sooner, but the anime becoming popular got him to keep the series going a little longer, and even released the scrapped original final chapter in the last volume release (140.5). As far as we know, the original final chapter may be the only thing changed from Hata's original game plan, with this arc being planned or written as long as the final chapter had been.
I mean, to be fair, its probably one of the only times we've gotten any real drama or stakes in this series, so I can see why everyone was so complacent and attached to the slice of life side of the manga, but it could be a lot worse, it could have ended up becoming a series like Kanojo, Okarishimasu, and have literally zero progression after the first chapter confession lol
I dunno, apparently I'm the only person reading this for the actual mystery behind Tsukasa's immortality with the slice of life chapters being the basis for the series' comedy and cute heartwarming moments focusing on their marriage and relationship, but the entire reason why any of that even matters is because she's supposedly immortal and having those kinds of relationships after being alive for centuries and dealing with literally everyone she cared about dying around her and eventually shutting herself off from those emotions and then meeting someone who makes her open back up is the entire point of the series, so why complain about the actual progression of the story's plot and mystery haha
Tbf I also kinda blame the funky release schedule lately, idk if its because of covid, or if the releases aren't steady on the translation/scan group's sites, or if its the magazine its published in, but the unsteady releases lately have messed with the pacing some probably, but again, its not like KanoKari where it took 170+ chapters to actually have some progress after literally every chapter ends with baiting the readers into thinking something was gonna happen only for the next chapter to basically retcon or purposely go out of their way to have it amount to nothing lol then again, reading this literally after Kanojo, Okarishimasu probably has me a little biased, but either way, the series finally getting into the actual plot of the story after so long, and adding some actual stakes and drama to the story for almost the first time since the first chapter when Nasa could have but obviously wouldn't have died is pretty nice imo. This series was never gonna last forever anyway, and we already got an extension after the anime instead of ending sooner like Hata wanted, so idk why everyone is getting so upset about the series finally addressing its main plot and moving it forward haha