Apple should provide an option to opt-out of Siri "learn from app" for ALL applications. At present, this must be done individually for every app, https://www.imore.com/how-stop-siri-learning-how-you-use-app... . When you later install new apps after setting up the device, you have to remember to go into Settings and opt-out again, for every app, forever. How many people know that iOS devices will default to Siri rea…
You can just disable Siri if you're that concerned? Edit: Turns out — you can't! See the reply below.
Apple fights you from disabling Siri as much as they can. I've tried to disable Siri multiple times, but it turns off other unrelated features/services, so it's basically impossible.
For example, if you're using CarPlay, it's required that Siri is enabled, even if you don't use the voice controls.