to be fair, not every artist has the same skillset and they need to learn the ropes one way or another, so it might be possible that the editor of the series, from the publisher, just decided to give the artist a go in this series. even artists needs some experiences, even if they include some failures, to learn, and while surprisingly many are picky about that one panel, it's not like all the art in this series is bad.
Except this doesn't meet any standards above the bottom-of-barrel one.
It shows no effort, no respect for anybody (reader, author, editor), much less any talent or even potential.
This was the laziest display I've ever seen, and I've read my fair share of cheap mangas out there.
It doesn't show failure, it shows no intent to try in the first place.
I'm not expecting top-tier level of skill. Just "decent" would be fine.
If you can't do urban landscapes, don't pretend. Pass it on to someone who can do the bare minimum you so obviously can't.
If you simply can't be bothered to try... well... maybe consider a different job?
I'm generally not too critical of barely average art, because I can acknowledge effort and skills particularly in a domain that I'm extremely bad at. (I'm barely able to draw stick figures with acceptable proportions, anything else is beyond me.) But this double-page doesn't show the bare minimum effort and respect for the audience.
It's not just bad, I see it as outright insulting.
Even if this single panel was delegated or subcontracted work, it shouldn't have passed any level of scrutiny and validation before submission.
The art of this manga is otherwise decent. Not bad, not good. Just ok, and that's fine with me.
Both story and art are pretty generic, but they meet the "decent" standard.
Which is why this panel stood out so negatively in comparison.