As much as /a/ hates to admit it, there is a market for dubs out there. Dubs require actors.
Though unless you worked as hard as the Japanese actors do, you'll never make a living off it by itself. They wouldn't either without being in so many shows at once and everything that comes with that (drama CDs, character song CDs, public appearances, etc.). By itself, voice acting is pretty much part-time job territory.