IMO it would make more sense to run every app in its own scaled down VM, like Microdroid for Android. Windows 10 had Microsoft Defender Application Guard for Microsoft Edge, and as far as security goes it was a fortress.

Too bad they discontinued it, and that performance was subpar. I would have loved to see them develop the idea more.

You want to keep a building secure, so you have some structure of access and key managment, who has access to what and who do you let in.

Then you let access and key managment slide, your front-desktop lets in some shady people and their is a hole in your back wall.

The solution: add scaffolding around the facade and empower some security service staff to enter every room through every window and chime in on every front desk decision.

I'm not sure it's doable with current OS architectures, though.