The 48 V DC "sweet spot" is mostly safety / regulatory. As soon as you get to 50 V, the safety requirements (NEC) change. You can hold on to bare conductors with a 48 V potential across them just fine, even though 120 V AC will kill you and make it hurt the entire time you are dying.

48 V devices can require connections that are inconvenient and large, depending on what you want to power with them. Try running an air conditioner off 48 V and measuring the peak current draw.

https://electronics.stackexchange.com/questions/267789/how-s...