…e actually designed instead of organically grown, developers almost universally chose to go native. But we lack anything good outside of mobile. We desperately need a way of conveniently distributing sandboxed, secure, auto-updating apps to desktops and laptops.
This is absolutely not the case. A Cocoa application on macOS distributed via the Mac App Store is exactly this, and the AppKit framework is the design inspiration for the UIKit framework on iOS and tvOS and very easy for developers familiar with UIKit to come up to speed on.