PWAs can appear to be a native app but are a saved website that is given OS access for things like local storage, push notifications and even allow for multiple copies of itself with different users. (Multiple mutiny wallets, for example) Also you get around centralized app stores. Damus had to recently remove the zap note feature because of a disagreement between @jb55 and Apple. If Damus was a PWA, then anyone could run it on nearly any platform and it could be updated without meeting any corporations rules for what your software is allowed to do.