The point is that having a webapp allows them to continue to serve users if their actual app is removed from app stores. It has no bearing on how their native app functions, whether it is in native code or a web wrapper etc.
This only applies because Apple runs a walled garden that is anti-user. People running actual computers with non-user-hostile operating systems can install whatever software they like. This is entirely apple's fault.
Websites are not applications. The browser is not an OS.
The point is that having a webapp allows them to continue to serve users if their actual app is removed from app stores. It has no bearing on how their native app functions, whether it is in native code or a web wrapper etc.