I mean you're not wrong, but what do you expect from a shounen manga/anime. Its aimed at younger teenage boys who are stigmatized for their hobby.
Its why you usually see loser/otaku x Popular girl in a lot of these rom com series. "Loser" describes both the author and the target audience, and the series are fantasies of them getting with pretty girls in class who would never look their way irl.
Dont get me wrong im kinda tired of the tropes, and how little effort a lot of the authors put in, but you dont really need to put the effort in when just the premise will draw the eyes of a lot of lonely young teenagers. This is why i tend to just stick with Seinen. There's still plenty of slop manga there ofc, but generally the loser protag trope is much less prominent.
You are making it sound like a shounen story
has to be shallow trope slop. Like there are no shounen stories out there where a relationship is developed around proper characters, where MMCs are more than self-insert blank canvasses. Like the author had no choice but do it like this.
I think that's giving the authors and publishers too easy an out. At the very least things should be said as it is: writing trope slop is a conscious decision that they made, not because the genre requires it, but because like junk food they can crank out generic garbage with minimal variation and that shit still sells reliably.
Meanwhile writing a story with some depth and actual characters has the potential to land you a highly acclaimed hit. Stories like Sono Bisque Doll or Kaoru Hana show that you can even run the loser/outsider + popular girl formula and still get something that isn't slop. But that also has much more potential at financially flopping if it doesn't generate a hype.
So of course they decide to do the financially responsible thing and go for the low risk, low but reliable reward option instead of risking their investments with a more volatile quality story. But again, we should call that what it is: a conscious decision by author and publisher.