Until these OS also start putting forward something like WebOS that tried to get phones back to on open web, there is no breaking the binary format and Appstore monopoly.
I wish Europe would have forced that 10 years ago since the US is beyond saving.
There's a huge open source app ecosystem for Android and it has the best support of any major platform for well integrated web applications. There are a bunch of alternatives for getting apps including getting them directly from the developers which has been automated without needing an app store. The linked post talks about using Obtainium for getting apps more directly from developers when possible.
Was WebOS really that much about openness? Are you not thinking of FirefoxOS/B2G?
What binary format?? Go read facebook's "source code", is that any more open than a random apk? If anything, apks decompile quite well.
So long as browsers allow you to open the developer tools and inspect memory etc., they're more open than remote attestation of a stock android or ios device
Decompiling apps only works if you can get the app. I don't understand GP's problem with the apk format either, but you do need to break terms of service to get the files if you don't have a phone with Google services installed. Whether that's ethical or legal is up for debate