Cortana is opt-in as well. When you first setup/install/boot Windows 10 there's a screen titled "Meet Cortana" where you can choose "Not now". When you first

Cortana is opt-in as well. When you first setup/install/boot Windows 10 there's a screen titled "Meet Cortana" where you can choose "Not now". When you first setup an iOS device it walks you through first setup and there's a very similar screen titled "Set up Siri". Android doesn't have such a screen. The difference between them is that Microsoft uses an Dark-Pattern to obscure the "Not now" option by placing it off to the left in normal font styling where as the "Next" button is a proper button.