Safari isn't the point -- running on other platforms is. Market share for iOS globally is nowhere close to Android; in India iOS is only about 10% so if your SwiftUI app could run in Chrome on Android and is installable as a PWA, you open up the rest of the handset market.
True. in fact they have a vested interest in not making this happen, but someone will. This looks really impressive and i've grown to like swift quite a bit.