Zafdor is right.
Digital aids with everything on a sealed chip should be more reliable than old fashioned analog discrete components and just as reliable as a chip based analog. Anyway most failures of all aids are due to moisture/sweat or abuse. Most often it’s the transducers or the battery doors that fail and that’s the same whether analog or digital.
Incidentally, TV failure rates dropped precipitiously when they switched to chip based architecture. Ed