[cjfd]

One problem is the idea that there is a one-size-fits-all solution. An application should be structured in such a way that it fits the problem that you are trying to solve as ergonomically as possible. 'Widget Driven Development' might be very good in some circumstances but not in others.

[alexey2020]

Agree. There are applications where widgets approach would not bring much benefits.

Let say, applications with lots of UI state (state that doesn't exist on Server).

Also not sure how it would work with realtime apps.

It's the same with every approach, the are always exceptions from the rule.

That said, I see the benefit of this approach for the majority of UI apps, which heavily rely on Server data.