What is that one series, that was either canceled or forced to have a rushed ending, that had the potential to be great but was cut too short to see it and you keep wondering, years later, how good it would have been had the author been able to continue?
For me its Saitou-kun wa Esper Rashii
https://anilist.co/manga/56651/Saitoukun-wa-Esper-Rashii/
It was some dumb comedy with an overconfident protagonist meeting actual espers which was so dumb funny to me, also it included a mind reader which is one of my favorite tropes in manga. It does have some of that 2000s and early 2010s ecchi which I feel has aged kind of poorly as it feel forced, at least for me. But the comedy is good, the main cast is funny and the protagonist is just really likeable in a sense.
Only problem is it lasts 26 chapters and the ending was so rushed it is nonsensical, I love this series but man when I reached the ending I was in disbelief seeing end that way.