As a web developer, I would love to see Safari implement the features addressed above, primarily first-class support for progressive web apps (including on the App Store) and notifications. If Safari implemented these features and nothing else changed, the Apple platform millions know and love would become significantly more powerful and let developers deliver consistent experiences for our collective customers.
That said, I would also like to add my voice for allowing other browsers on the Apple mobile ecosystem rather than re-skins of Webkit. While mobile Safari is an amazing technology, increased competition is better for users and drives innovation, compromise and collaboration in the standards process that I believe would benefit everyone.