I find it advantageous to load up hi-res music on a micro-SD card, means I’m not swamping my phone’s storage with music. (Well, I am, ‘cos I keep my phone full of lower-res lossless as well.)
Also, if you use an iPhone, connectivity to the Mojo is dependent on the whims of the latest version of iOS and the Apple CCK cable.
The Mojo/Poly can be great when it works, but I’m not convinced it isn’t running some kind of super-advanced AI to come up with ever more elaborate reasons for not working. Hands down the most frustrating audio product I’ve owned in 40 years of faffing around with the stuff.