If by native you mean compiling to machine code, then Android's Java VM isn't a native platform to run Android apps on
If you mean that it won't work offline, websites apparently can. I've not seen it done reliably yet but in theory that's there and I'm sure we can work out the kinks if needed
Not OP, but native in this context usually means using the platforms widget toolkit and application frameworks. So that for example on iOS, your app looks (and feels) like one of Apple’s own.
Modern web is a platform.