Comment by john_alan

What about all the stuff they've done to keep it open:

- Per-install boot security policies

- Custom kernel boot (kmutil configure-boot)

- Raw-image boot mode

- XNU source releases

- Disabling SIP

- Disabling the Signed System Volume

- Third-party kernel extensions

- Developer ID distribution and notarisation

- Gatekeeper "Open Anyway" override

- Hypervisor.framework

- Virtualization.framework

- Rosetta for Linux VMs

- Nested virtualisation

- macOS guest provisioning

- DiskImageKit

- Custom Virtio devices

- Containerization framework