Sorry Ara team; but the whole concept is a fail.
I do lots of electronic product development, and this concept has so many problems
- Electromagnetic Compliance. Every time a new module is created, are you going to go through the expense & time of compliance testing.
- Where is consumer demand for such a device? Consumers are becoming dumber; they are flat out finding a power button, let alone selecting complex modules for a phone. This makes it a niche market device, thus low volume, thus expensive.
- Connectors in any design are one of the common fail points. In this design you have lots of them.
- There's a lot of effort just to reliably mechanically retain the modules.
- Having discrete modules makes layout inefficient, as you have to per-decide the size of a function.
- A lot of added complexity/power consumption, as each module needs a hardware/software interface layer common to all modules to abstract their native interface.
- plus all the other mentioned in the link
Now if Google has some spare cash lying around, I've got a lot great projects going on they could invest in!!!