not only is it all super important plot setup for later (if they skipped over it like the manga, they'd p much have to do it later anyway? and then instead of short asides it'd have to be full episodes of them)
but honestly the biggest weakness of early-spiderskai is in the lack of characters and dialogue in spider portions. you've got her, talking to herself, and then fighting monsters
The accelerated speed in general is pretty much my one complaint with the series - so many things get left out on all sides. There's several things even for spider portions that just straight up never get explained, and it's only my knowledge as a book reader that keeps me from going "Wait, what?" (It's mostly small stuff tho)
who switches up between like really high formal she sounds like she belongs and then "man watch yourself dude" with this change in tone that completely conveys her former life
especially Fiel and Arielyeah,,