This is true, but it’s worth nothing that the protections are improving, and without the walled garden that wouldn’t be possible.

> without the walled garden that wouldn’t be possible

Aren't many of these protections at the OS level? Certainly apps installed from 3rd party App stores on Android still have to use the same permissions system/etc as those coming from the Google Store.

Some are at the OS level, but many are not.

For example straight up fraud and phishing, or botnets, or Apps that abuse permissions.

Many of these have no technical countermeasures and have to either be rejected at review time, or removed when discovered.

User facing monitoring is a huge help here. I removed an application that hijacked the lock screen of a phone with Android 4 on it (Android only had the requirement that applications don't hijack the lock screen from the App Store for Android 5 and up IIRC). This was because of the simple monitoring that was built into Android through developer options which was simple to activate.

Far more could be done with more sophisticated user controlled monitoring tools, which could say monitor the network traffic, application accesses to any information on the device etc. No reason it cannot be done, and they may be there already.

Also device does not need to have their applications mandatorily locked to an App Store to get the benefits. Optional use of the 'official' app store is fine too, which is what isn't there on iOS. You can choose to just get your applications through the 'official' app store. Someone else not getting their applications through the 'official' app store does not magically put those applications on your device, and thus does not decrease the security you may get from the app store for you.

How can ‘user facing monitoring’ help a non tech savvy person tell the difference between a fraudulent app that and a real one that otherwise looks the same?

As as for ‘you can just choose the official store’ - it’s not as simple as that. There will be a giant campaign to get people to install alternative stores because the official one is evil and locked down.

People will do so without having the ability to tell which alternative stores are legitimate and which are not.

That can't be true, privacy protection is only possible in a walled garden? So I can't get privacy on Linux? Even on Tails?

Can my non English fluent non computer literate parents get privacy on Linux, with an insatiable need to click on every link they see in WhatsApp?

Yes, and out of the box, too.