[jsnell]

Apple has been abusing their dominant market position for more than a decade, blocking browser competition with security being one of their excuses. They can't be trusted to be honest about what's a legitimate security issue, and what's just them using security as a smokescreen for anti-competitive behavior.

And in fact, they are not being honest in this very case. Their entire spiel is based on the idea that the 3rd party browsers will be malicious, and permit data sharing between different PWAs. It's a risk they've just made up, because they're already making all kinds of other security requirements on 3rd party browsers before allowing them on the platform. They could just have made this one of those requirements.