Maybe this is relevant? I worked in animation and VFX for an Academy Award winning VFX studio and several well known animation / game studios, starting around '90. I formally left the industry around '04 to work on my own tech startup. When I left, there was a lot of R&D work surrounding the huge amounts of data that an animation studio generates and works with; I was one of those people creating early deep learning systems for production forecasting.
Anyway, right around '10 the industry was really stressed. The financial crash was 2 years in, and the recovery was more propaganda than reality. The productions were chasing a Hollywood market that the population did not have the disposable income to support. Then in all that stress, the Me-Too movement starts. Rumors and murmurs at first, but soon a tsunami of women from the entertainment industry sharing their institutional abuse and choosing to leave the industry entirely. My wife was one, an Academy Award winning filmmaker, famous for children's media.
That line in time of Hollywood films going bad? It is when the women that were silent in their abuse chose to leave the industry enmasse. What replaced them were clueless men and women okay with the abuse, and the reduced quality of Hollywood is a reflection of the quality of their intellects.