> It should obviously use the webview facility provided by the default browser
Android doesn't do that either. You get Android System WebView which is always WebKit/Blink.
Windows didn't provide any browser engines apart from Trident through mshtml.dll either.
It would make iOS development harder - instead of getting a web view working just for WKWebView, you would need to get it working for every WebView out there. Given that they are not full browsers, it's not as simple as following web standards/caniuse. For example, service worker support in in-app browsers is limited.
If this actually gets implemented, every app out there will most likely pin the in-app browser engine to WKWebView OR bundle a binary blob with their own browser engine directly into .ipa. Bundled browser engine in .ipa has privacy implications - the app will be able to fully read secure HTTPS cookies of the sites that user visits - something that's currently protected.
> [...] if you set [Firefox] as a default browser you will many apps open content in a Firefox powered webview. (Activity)
This is great because the Firefox webview allows to break it out in to a proper Firefox tab in the app. Also, the Firefox webview also uses extensions installed in Firefox app, e.g. uBlock Origin.
Thanks to you and others for pointing these out. I want to make clear that this isn't the EU's list and is just stuff I could observe disregarding my default browser choice. But if there's good reasons, by all means, don't make developers' lives hell.
Android doesn't do that either. You get Android System WebView which is always WebKit/Blink.
Windows didn't provide any browser engines apart from Trident through mshtml.dll either.
It would make iOS development harder - instead of getting a web view working just for WKWebView, you would need to get it working for every WebView out there. Given that they are not full browsers, it's not as simple as following web standards/caniuse. For example, service worker support in in-app browsers is limited.
If this actually gets implemented, every app out there will most likely pin the in-app browser engine to WKWebView OR bundle a binary blob with their own browser engine directly into .ipa. Bundled browser engine in .ipa has privacy implications - the app will be able to fully read secure HTTPS cookies of the sites that user visits - something that's currently protected.