I think it should display one or the other dynamically, depending on the situation. Show % charge coarsely (like the battery icon on your laptop) when above a certain level, or when distance to the next SC is in not jeopardy. Below that threshold, show miles.
My logic is that we rarely had range anxiety in our ICEs, only partly because we had sufficient range. The other reason was that the car had a "blunt instrument" in the gas gauge, a thick needle on a poorly marked scale. Our EVs are now capable of a sufficient range that we really don't need to worry about it, so the constant reminder of exactly how many miles we have left is probably causing more anxiety than it solves. Out of sight, out of mind (in a good way).
Now, when you're getting low on charge, as when we got low on gas, accuracy and precision are big helps in the management of the vehicle. In the ICE we still had the blunt instrument on the dash (though some cars got creative with a second needle that popped up when you were below 1/8 tank), and the accuracy in reading how much juice was sloshing around in the tank was never very good to begin with. With our EVs and their instrumentation we're far ahead in that department. When it counts - when things get tight - we should play that to the driver's advantage, and show the estimated range remaining, along with distance to the next charging stop. Also, the appearance of the remaining range as something different on the screen (vs just the icon) draws attention to the situation, making it less likely for someone to get stranded.