Tangent: wouldn't it be nice if you could say "Siri, ask Google to..."

I wonder if implementing the feature of calling 3rd party assistants from the flagship assistant would pay off strategically.

On one hand, you appeal to people who like other assistants better, or like different assistants for different things. On the other hand, you give up on forcing people to get used to your assistant.

Also, could an isolationist provider stop other assistants from calling their one? Technically? Legally?