What problem does this feature solve?

While we can access the returned type information of Vue native apis (i.e. data, computed, props, methods), the return type of asyncData function is totally lost from "this" object.

I'm not sure if it's even possible to combine these type information without changes on Vue core types, but I believe it is 'must-have' goal for us to provide safe, correct, efficient type definitions for users.

I've already spent some hours to solve this problem yet I haven't seen a daylight. Hope I can rely on your help.