Digital circuits also process everything in parallel. It's only CPUs (i.e. one particular thing you can build out of a digital circuit) that have trouble with

Digital circuits also process everything in parallel. It's only CPUs (i.e. one particular thing you can build out of a digital circuit) that have trouble with it, really... Quantum computing is (somewhat) analog in nature, but it's not "just analog". In theory, taking advantage of quantum physics in the computer gives you an improvement in asymptotic complexity (not just a constant factor speedup), one that you can't get any other way.