A lot of the time, successful VO actors are cartoon lifers. Once you figure out how to sound like 90 different people, your precious vocal cords matter a lot more than your pretty face.
Still, voice actors do manage to make it to live-action once in a while. Similarly, TV and film actors sometimes get their start in the world of cartoons before they catch their big break IRL. Here are a few times some extremely recognizable voices or faces successfully crossed mediums: