If you bump up voltage you simply move power loss from cable to the phone step-down electronics.
I prefer a warm cable than a warm phone, it makes the phone faster while charging.
What I don’t see a legitimate argument for is other than PD as it supports the high amperage 5V which would do what Dash does.
One other important fact is if I am out for more than a few hours I am always with a Powercore anyway so I don’t really need fast charging for a phone. Where is need higher Wattage is my largest tablet. My 10.8" tablet barely recharges at 18W while used.
So what I’m saying is Dash, for a phone, does not need to exist, it solves a faux problem of someone goes for hours between wall sockets and carries their wall charger only. Why would an intelligent person do that when a Powercore of comparable size to the Dash charger holds about 2 phone recharges.
My EDC is either the original Slim 5000, or the Powercore II 6700 or the Powercore PD 10000, depending on if pockets or bag.