AFAIK historically Home Screen web apps were run in a separate runner from the main Safari based on the web view control, and thus limited. There was a time the

AFAIK historically Home Screen web apps were run in a separate runner from the main Safari based on the web view control, and thus limited. There was a time they didn't get native JIT for javascript, either. My suspicion is that they internally treat it as their own third party browser - e.g. they don't want to give it more entitlements/capabilities than a Firefox or Chrome browser would have from the iOS app store. My suspicion also is that they have had a bit more wood behind the arrow to get media APIs working lately due to pushing large third-party cloud game subscription services to use the browser, and the regulatory scrutiny that likely brought on.