With Apple making its Sign In with Apple feature mandatory for App Store developers, it starts to feel less like competition and more like brute force
Casey Newton / The Interface :
Context & Ripple Effects
Casey Newton's column lands days after WWDC, where Apple turned Sign In with Apple from an optional privacy feature into a requirement: any App Store app offering third-party logins must offer Apple's button too. The framing builds directly on Newton's earlier argument that Apple shutting down Facebook's internal iOS apps was a reminder of the power Apple holds over everyone else on its platform.
The privacy case is real — the button was designed for a post-Cambridge Analytica world where users want minimal data handed to apps — but the mandatory rollout is what converts a product into leverage, and it immediately drew mixed reactions from developers who must now implement a competitor's login alongside Google's and Facebook's.
First-order effects
- Developers offering Google or Facebook sign-in must now build, test, and maintain Sign In with Apple as well, adding a mandatory integration to every app with third-party authentication.
- Apple inserts itself into the identity layer of every major iOS app, positioning its button as the privacy-preferred option at the exact moment users choose who holds their login.
Second-order effects
- Google and Facebook lose default placement as the sole third-party login options and now share the sign-in screen with the platform owner, who also controls whether their apps pass review.
- The mandate feeds the broader anti-competitive scrutiny of the App Store documented in the OneZero examination of iOS restrictions, and by 2021 it drew a DOJ investigation into whether the button makes switching to rival devices harder.
Third-order effects
- If the pattern holds, platform gatekeepers will keep converting privacy positioning into mandatory infrastructure — and each mandate becomes evidence in the regulatory case over whether access-layer control itself is an antitrust problem.
- Identity becomes the next battleground where Apple's rules effectively set terms for competitors' businesses on iOS, the same asymmetry Newton flagged with the Facebook app shutdown.
The trend: Platform owners are converting privacy features into mandatory access-layer infrastructure, and each mandate deepens the regulatory scrutiny of gatekeeper power.