I wear out rear shift cables in 2500 miles (got worse when Campagnolo moved the 90 degree bend from the cable housing to inside the shifter) and housing 4000 (got much worse with lined housing), which means service every 10 weeks.

Hydraulic would avoid problems like that, although it's late to the party with electronic shifting allowing an arbitrary number of optimally located shift controls, automatic front derailleur trimming, and potentially useful software options like hitting buttons on both shifters to arrive at the next gear on a ring change.

Running out of battery power would be bad, but with a decent gauge and known life it's not a problem for cellular users (at least those of us not using GPS aps which can drain a battery in hours).