To me that highlights how important it is for UI frameworks of all types to have accessibility affordances not only built in, but as one of the pillars of their designs. That makes it so even apps developed without any regard to accessibility are reasonably accessible by default.
This doesn't gel well with the bring-your-own-everything nature of the web, unfortunately. Even if you look just at React there's 50 ways to build the same thing, which I'm sure makes rolling in accessibility that "just works" across all React apps without additional effort from the developer extremely difficult. It's much more practical with UI frameworks that are strongly opinionated with only a single well-supported "happy path" for most things.
This doesn't gel well with the bring-your-own-everything nature of the web, unfortunately. Even if you look just at React there's 50 ways to build the same thing, which I'm sure makes rolling in accessibility that "just works" across all React apps without additional effort from the developer extremely difficult. It's much more practical with UI frameworks that are strongly opinionated with only a single well-supported "happy path" for most things.