Supporting that higher voltage requires hardware support on both ends and also active negotiation on both ends so the devices can agree what voltage to use. (Without that it falls back to the old USB default 5V and a much lower max power)

Recently a friend was charging about six different items off of his PC. Not mentioning the poor charging rate. I said to him, hey, maybe you want to get a dedicated charging hub for 40 bucks instead of putting wear and tear on the $250 motherboard and power supply. Just because you can, doesn't always mean you should.