Some UX modalities work at multiple levels of abstraction.
A map works the same as you zoom in, with the level of detail changing.
Chat also has this characteristic.
You can cover high level topics, or detailed ones, and bounce up and down the abstraction layer.
Chat allows malleability, but in an annoying text-only form factor.
Use cases bounce up and down the ladder of abstraction.
But apps don't have that characteristic, so they can't come with us.
Apps are locked in a given level of abstraction.
As a result, we as users must do the climbing up and down the levels of abstraction.
Hopping across different apps.
Because each app is an island, the human has to bring the context with them.
This happens UI needs software to generate it, and software is expensive.
Infinite software might change that.
The answer is not "design an app on demand" because apps are isolated islands.
What you want is your context to come up and down the abstraction stack with you.
A system that allows you to fluidly and safely bring context to arbitrary UI would be amazingly powerful.
Any single example of a single screen would just be "X, but with data autopopulated".
But the real power would become clear in use cases that bounce across different layers of abstraction, as real tasks do.