It's a different set of trade-offs.
* Theoretically; I don't own an iPhone.
Server side means shared resources, shared upgrades and shared costs. The privacy aspect matters, but at what cost?
The cost, so far, is greater.
How so if efficiency is key for datacenters to be competitive? If anything it's the other way around.
Local doesn't cost the company anything, and increases the minimum hardware customers need to buy.