A choke on an engine does not do anything other than control the flow of air to the engine. That's it. That's all it does.

Allowing the URL bar to also act as search or vice versa, the simple act of trying to do the one thing now does something else that you might or might not have intended or been aware of being possible is not the same as a single purpose choke. When that possible thing is sending your data to a 3rd party, then that is just bad.

Edit: finished an incomplete thought