FWIW you can of course implement createSignal in four lines of code, if you prefer the ergonomics of that:

function createSignal(initial) { let value = $state(initial); return [() => value, (v) => value = $state(v)]; }

Note that the Solid change is _not_ 'one step' — the `completed` property is being turned from a property to a function, which means you must update all the usage sites as well. Using getters and setters also allows you to use Svelte's convenient `bind:value` approach, which is much less verbose than using the equivalent event handler code. And don't get me started on the [type narrowing issues](https://www.typescriptlang.org/play?#code/C4TwDgpgBA4hzAgJwD...).

There's nothing _wrong_ with the Solid approach, but the ergonomics aren't to our liking. If we need to take a hit in terms of verbosity, we'd rather do it once at the declaration site than n times at every usage site.