Good read, but a bit boring and predictable near the end.
If it ended early as the author intended, then it's an ok point to end the series. There aren't a lot of "good" ways a manga with OP protagonists will end, at least not without tackling some serious issues too, but I can see the author wanted to keep the lighthearted feel so I can respect that. Else it'll end up like Mob Psycho or One Punch Man. Nothing wrong if that happened of course, except abandoning the lighthearted feel.
If the series got axed because it did get a lil meh for me near the end, well, RIP.