Earlier quoted context omitted.
Have to agree (disclaimer, haven't been an iPhone user since the 4). Suddenly allowing all browsers to have those kinds of native permissions, even with massive testing, sounds like a security nightmare. You're introducing an entire extra dimension for security holes, given how much trust people place in their phones. This doesn't sound at all the same as allowing other engines for use inside browsers, based on both…
Browsers support PWAs on the desktop platforms without there being a security nightmare, and while I'm sure there are some permissions that could be a problem, things like the camera and microphone are managed on the desktop without issue. Is there some flaw in iOS that makes it harder to secure than the desktop?
So... yes, there is apparently a lack of security there, but that's because the layer in question was never intended to be anything but proprietary until this ruling.