I did watch the Spider isekai. The show was split into two halves.
As for the Spider protagonist, I remember that she was quite boring to follow. She encountered no difficulty. It is hard for there to be any tension to keep you wanting to find out what will happen next when any crippling damage done to the protagonist is reversed 30 seconds later. Ate a poison worm that is killing you from the inside? No problem, just level up and your HP goes back to max again! Got your leg torn off? No problem, just level up and regrow a leg! Got bitten in half? No problem, just level up and your body is as good as new! Also hard to feel that the protagonist will be in any danger after she soloed an army of 1,000 monkeys. The spider's story becomes more interesting to follow once she gets out of the cave, but that takes a dozen episodes.
The blue haired mage boy and his talking pet were more interesting to follow at first. The blue talking pet burdened with regrets was the most sympathetic character in the show. It was dumb that no one recognized the obvious. "Hm... demon forces are setting up near every military installation and place of strategic importance in the world... I think they are about to launch a simultaneous world wide invasion!". The human story fizzles out and becomes boring to watch around when the spider gets out of the cave.
The 3D CGI later on was dreadful, and also puzzling for a 2021 show. The 3D CGI armies in the 2006 Utawarerumono anime looked better.