Light Novel Pet Peeves

I read around 200 volumes of light novels per year and generally, I really enjoy my time with most of them. But there are some things coming up again and again in many light novels that make me angry. I'm sure everyone here has some light novel pet peeves and I'd like to hear what they are. Here are some of mine and my thought about them:

• Extremely oblivious main characters: There are so many main characters, especially in isekai stories, that are ridiculously overpowered but somehow still behave like timid little lambs that are scared of every random trash mob. I have no idea why this is something I see so often. My working theory is that it is something related to Japanese culture where assertive personalities are generally disliked. Especially by the default target audience of those types of power fantasies. This would also explain my second pet peeve...
• Extremely passive main characters: I hate the terms "alpha and beta males" with a passion, but why oh why are so many light novel protagonists such hopeless omega males? Are authors really so scared to lose their audience if their main character doesn't let everyone trample all over them? I don't mind it if a character has a timid disposition but the extremes in which some characters are portrayed in this regard are just beyond the pale. I simply cannot fathom how anyone can enjoy reading from such a character's point of view. To me, it's just infuriating.
• Isekai element not used as a plot device but a narrative crutch: A.k.a. "Isekai for isekai's sake". Let me explain what I mean. Every now and then I read a isekai light novel and wonder why the hell it is an isekai in the first place. The only way they use the isekai element is as a crutch for newbie authors to help explain the world to the reader. Writing good exposition prose seems to be a hard problem to tackle. But instead of trying to write some good exposition I often get the feeling many authors just go the isekai route instead. After all, if the protagonist doesn't know anything about the world it's normal to have him question even the most mundane (mundane to the inhabitants of the isekai world) things. It's also easier to say "The monster was as large as a bus" than to explain it in fantasy-appropriate terms. Compare this to something where being from another world is used as a major plot device instead. For example, Myne using her knowledge to create printing presses in Bookworm. But this is also something that can backfire, which would bring me to my last point...
• Protagonists somehow having extensive knowledge about things outside their sphere of expertise: One example would be a isekai lightnovel (was so utterly forgettable that I can't even remember its name anymore) where some high schooler (obviously) could recreate modern weaponry and car engines from memory. Authors often think having a general knowledge of how something works is enough to recreate it with no problem. Using Bookworm again as a positive example I'd like to point out how much time is spent by her and the other characters in this story on R&D to turn her general knowledge into something actually actionable. But no, some protagonists can apparently just recreate a pump action shotgun because they've seen in movies how they are used. Who cares about the workings of the mechanical parts of the loading mechanism, the chemical compounds of the blackpowder (and how to get those in the first place) or how to create a firing cap. I mean, this is a fantasy story, why not come up with some random shit why it works? Like in Average abilities for example with the magic system build on sentient nanobots that figure out the pesky details for the protagonist instead of trying to sell me that a high schooler would have the knowledge to create something from scratch.

I have a lot more pet peeves that trigger me but I'd like to hear yours instead of writing another wall of text.