Why createRef setter not compare old value with the new?

[Maorey]

Version

3.0.0-beta.3

Reproduction link

https://github.com/vuejs/vue-next/blob/6fefeafe988b1e1f14224dfb11b87d4710042313/packages/reactivity/src/ref.ts#L58

Steps to reproduce

import { ref } from 'vue'

export default {
  template: '<button @click="inc">Clicked {{ count }} times.</button>',
  setup() {
    const count = ref(0)
    const inc = () => {
      count.value = 0 // not change
    }

    return {
      count,
      inc
    }
  }
}

What is expected?

do nothing

What is actually happening?

triggered