How should you know whether it's about accessibility? The `prefers-reduced-motion` feature is explicitly[0] intended to accommodate people with vestibular motion disorders, which are common above age 40.[1]
If it's really bad, couldn't they apply userstyles that disable all animation with `!important`? `prefers-*` settings seem somewhat optional, best-effort, based on their name.
[0]: https://drafts.csswg.org/mediaqueries-5/#prefers-reduced-mot...
[1]: https://vestibular.org/article/what-is-vestibular/about-vest...