Okay, thank you, I appreciate the far more detailed write up.
I can't actually answer why every indie game that goes for Metroidvania goes for a visual gimmick, but I do agree with you that it does. Personally, I'm not that bothered, inasmuch as the design and aesthetic doesn't disconnect me from the world- in the case of Hollow Knight specifically, I found the ambience to be incredible, and it pulled me into its world deeper in spite of the bug aesthetic, as well as the generally moody look. That said, I get it- if the whole gimmick is off putting to you, and not to your liking, yeah, it instantly takes you away from the world, and from your own character, and investment in your own world and your own character are basically paramount to be able to enjoy a Metroidvania game fully.
I am not entirely sure about your final point, in context of the discussion, though. For instance, in the SNES era, Super Metroid absolutely tries to make you feel something with its story. The destruction at the space station at the start is supposed to make you feel dread and hopelessness, you are supposed to feel helpless against Mother Brain, you are supposed to lament the baby Metroid's sacrifice at the end. Super Metroid is a master at storytelling, of course, so it can often be hard to perceive what story it is trying to tell because it does so so effortlessly, but it does tell a story, and there are very clear emotional beats it tries to hit. In that regard, I don't know that I would agree with you that Hollow Knight is any different.
Anyway, thanks once again for the far more detailed write up. I'm sorry for my earlier hostility, there's just so much shitposting that often happens in these threads I wasn't sure that your post wasn't meant to be one of those.