Why can't endpoints not return pages yet?

[UltraCakeBakery]

What is the technical / philosophical related blocker for page endpoints not being able to return pages? I have a __layout.svelte that has a ModalManager that, based on the current page, through $page.stuff, mounts the required modal components for that page.

I now run into a blocking issue: I can't return errors or data to those modals when the forms inside them post to an endpoint.

I was hoping I could do something like:

// layout-modal-component-form-handlers.js
export function get()
{
    return {
        body: { errors: { modals: { login: ['Your password has expired'] } }
        page: '/home?modal=login'
    }
}

But this sadly isn't a thing...

Are there workarounds available for this kind of scenario?
Is this feature considered for 1.0?

I have seen talks about a feature like this when page endpoints got introduced. Also when people were talking about layout endpoints and renaming layouts to __section. So this idea is not new or never brought up before. Why is this not a thing or not considered (yet)? Will this be considered? How can I get this to be considered?

A feature like this could make the concept of page endpoints obsolete and make producing more complex no-javascript-first / static application possible.

[UltraCakeBakery]

This now a thing. Check the routing docs