The question now is what are the functions of App Store. Search and purchase convenience? I guess so - but that is easy to replace and substitute. The real one

The question now is what are the functions of App Store. Search and purchase convenience? I guess so - but that is easy to replace and substitute. The real one is security vetting. We see more and more problems in this area (with back doors injected in Open Source libraries, which maybe was just the visible part, because similar attacks would be much more stealthy in closed source). So it is more and more important. Can it be replaced? I don't have much expertise in this - but it seems to be very deeply intertwined with the operating system. I like to use the Christensen/Ben Thompson framework of integrated and modularized systems: https://stratechery.com/2020/chips-and-geopolitics/ https://stratechery.com/2020/chips-and-geopolitics/. But how that appliess here? Phone is a 'good enough' product now - so it should be modularized. But how can you do security in modularized way, how security could be separated from the OS? Maybe we need more vm based sandboxes ala QubesOS?