Earlier this year, we launched Richer Install, an extended install UI on Chrome on Android that allows developers to add screenshots to their manifest. Developers can also add a description, which is recommended but not necessary. Due to this newer UI, we saw an install rate for some PWAs double, showing that users have greater confidence in installing web apps when we give more context and richer experiences.. The desktop version of this UI is currently a work in progress.
It would be really great to see something akin to Richer Install for iOS. But unless regulated to do so. I have no hope that Apple would ever give the web the standards it deserves.