> $state and $ref are quite different.
I wouldn't say they are "different" - they are fundamentally the same thing: compiler-enabled reactive variables backed by runtime signals! But yes, Vue already exposes the underlying concept of refs, so for users it's two layers of abstractions. This is something that Svelte doesn't suffer from at this moment, but I suspect you will soon see users reinventing the same primitive in userland.
> There's strict read/write separation
I'd argue this is something made more important than it seems to be - we've hardly seen real issues caused by this in real world cases, and you can enforce separation if you want to.
> We're instead encouraging people to use familiar JavaScript concepts like functions and accessors
This is good (despite making exposing state much more verbose). In Vue, we had to introduce destructuring macros because we wanted the transform to be using the same return shape with all the existing composable functions like VueUse.
> There are already a lot of different ways to work with Vue
This is largely because Vue has a longer history, more legacy users that we have to cater to, so it's much harder to get rid of old cruft. We also support cases that Svelte doesn't account for, e.g. use without a compile step. That said, the default way with a compile step is now clearly Composition API + . Reactivity Transform also only really applied in this case so the point you raised is kinda moot.
Separate from the above points, the main reason Reactivity Transform wasn't accepted remains in Runes: the fact that compiler-magic now invades normal JS/TS files and alters vanilla semantics. Variable assignments can now potentially be reactive - but there is no obvious indication other than the declaration site. We had users trying Reactivity Transform on large production codebases, and they ended up finding their large composition functions harder to grasp due to exactly this (and not any of the points raised above).