I'm fine with Apple retaining interoperability between their first party software products, they just need a way to bypass the walled garden. If they have sideloading (everywhere and without restrictions) and ideally also bootloader unlocking, they provide a sanctioned path around the walls of their ecosystem and now it's up to the user to choose to leave that garden. If the user is comfortable there, they can stay. Trying to fuck over sideloading is the issue here. I'm fine with the App Store being restrictive if there's a way around it, and simply sideloading an app shouldn't break the rest of the OS's capabilities.