Web apps are just as "real nostr clients" as any other app.

They all requires servers one way or another, and if a relay doesn't update their certificate, no data will flow, no matter if your app is deployed from a centralized corporate approval system (Play Store/App Store), that can wipe your app off the earth by will, or if your app is downloaded from a git repo or web server to be installable, or if it's retrieved using web technology.

There is also a big difference between a client web app and server web app. Any server web app has an online dependency. Any client web app is just like any other native app, just using web tech for rendering.