While I'm a little disappointed this manga ended, I'm not surprised. The recent arcs and the whole "physically beat me to date my daughter schtick" thing that was taking over was not only a boring (and outdated) cliche, but also drained all the fun out of this comic.
Plus, it pushed all of the fun and interesting (arguably more interesting than the main characters) side characters out of the way and locked the narrative into a predictable path with no variety. This manga could've continued past the point where people got into relationships the way Working! (the TV show, I haven't read the manga) did so long as it was willing to organically grow the characters, and find a way for them to interact naturally in the new situations they found themselves in entertainingly.
Some have remarked that the author doesn't seem to know how to portray romantic relationships well, and while I haven't seen his work enough to say that it's the case overall, with this partical manga, I feel like he hasn't done that. If it had focused more on the comedy with the romance as an aside, I think it would still would have continued.
Also, I went back and browsed the first few "chapters" again, and wow, the feel of the manga back then compared to now is much different, and it was much better at the beginning. Page-turning, and full of life. Maybe these character and this work will be revisited someday, but hopefully after the artist's gotten some new inspiration and learned and grown enough to do it more justice.