Try using that watch with Android. That's where the walled garden is. Or try writing an app that does complex stuff via NFC. Or a browser engine. Or another app store like fdroid. Or an emulator. Or sideload the apps that Apple doesn't want you to have. Etc etc.
You can do so much in apple's garden that you may never need to leave it, depending on your usecase. If you don't run into it, it doesn't mean the wall isn't still there.