I don't understand the trend towards modular phones, such as what LG recently announced and Google's Project Ara. Who wants to carry around a bunch of little hardware bits to plug in and out of their phones? 

More than a decade ago the Compaq iPaq had a similar system of sleeves to expand its capabilities. I could plug in any PC card with a sleeve that had a big additional battery, or a Compact Flash card with another sleeve. As much as I liked the flexibility these sleeves provided, they tended to multiple quickly.