24v and 36v are common in trucks and industrial vehicles respectively for exactly this reason, among others. It's really expensive to increase voltage though because all the different components' power supplies have to be designed for transients and supply voltages anywhere from 2-5x nominal in normal operation. Companies will often design up to around 200v, for example.

High power systems do exist, particularly in electric vehicles. They have different challenges to do with being incredibly dangerous to work on.