What a nice language for constructive discussion...
And yes. Because it's not just a simple HTML+CSS website, your browser must pull full-featured, Turing complete compiled to JavaScript code and execute it in order for GitHub website to work.
There is no much philosophical difference between running JavaScript on V8 engine in Chrome and running Kotlin code on ART in Android.
Just becasue you don't see app icon being added to homescreen doesn't mean there isn't downloading and running an app.