What problem does this feature solve?

expect the ref sugar can support to object destructuring , because via toRef to convert reactive objcet will must to use .value to get value

What does the proposed API look like?

// example ref: { dummy } = props;

const a = reactive([1]) ref: [b] = a; // expect it can be worked console.log(b) // 1

const c = reactive({d : 1}) ref: { d } = a; // expect it can be worked console.log(b) // 1

I think you should put it https://github.com/vuejs/rfcs/pull/228, and discuss it there.

vuejs/rfcs#228

yep, thankssss