Because that's literally what it says when you really read into it? They acknowledge that 1) Safari already has all the integrations required to support PWA securely and that 2) they can't be bothered to provide the same API's for third party browsers because it's not "practical".
They built their PWA support in an anticompetitive manner assuming App Store & WebKit would be a monopoly forever, and now as a result the baby is going out with the bathwater.
They built their PWA support in an anticompetitive manner assuming App Store & WebKit would be a monopoly forever, and now as a result the baby is going out with the bathwater.