You seem to prefer guesswork to facts. Google offers line by line specifics for every app regarding access. Apple demands full access or the app doesn't operate as designed. Once again Apple dictates without choices. Conversely Android is full of choices. There's a huge amount of freedom.
You are correct. If you don't allow the Android app access to everything when you install or update the keyboard/app, you can forget about it. Android just tells you what it needs access to.