Have a look at the remakes of Berserk or Sailor Moon. These are two of the most high-profile anime and manga franchises out there and should have plenty of financial backing, yet they look WAY worse than their cel animated counterparts from the 90s.

https://mangathrill.com/wp-content/uploads/2020/12/pjimage-2...

https://static1.srcdn.com/wordpress/wp-content/uploads/2017/...