Yes, but you can have this by providing surfaces as UI components to Siri.

Not sure if they do that (yet), but no reason an app couldn’t expose "Here’s what you can use to present data of shape X", or "here’s a UI for process doing y".

It feels like turning the common approach inside-out. But it works.

Edit: you could even imagine, in that world, apps that only expose surfaces, composable UI libraries, multi-step flows, declaring what they’re for, what kind of inputs they take, and what output they produce. Without ever owning any of the data (eg flights data, hotels inventory, booked trips, financial data, etc) or capabilities (eg book a flight).