What problem does this feature solve?

when using css modules, the deep selector '>>>' does not work at all, when using css scoped it works fine, would be great if css modules has this feature

What does the proposed API look like?

<style lang="postcss" module>
.container  >>> .children {
  color: red;
}
</style>
// should be parsed to

<style type="text/css">
.container_Xz11 .children{
  color: red
}
</style>