Because they did not use electric motors.

Now SiC MOSFETs are the most efficient devices for the power converters used in electric vehicles, where DC voltages of 800 V or 1000 V are used in the latest models, which require, respectively, 1200 V or 1400 V SiC MOSFETs.

GaN HEMTs (high-electron-mobility transistors) are the most efficient devices for the power supplies that are fed from mains electricity, where 650 V GaN devices are used for the universal power supplies, which must accept up to 240 V AC on input.

I'm curious about RF uses (esp phased-array radar / AESA). usually GaN is treated as the the best for power/efficiency reasons, but does SiC enter into the picture? not fast enough?

...Can't we just go back to thermionic vacuum tubes at this point? Those worked just fine at kilowatt powers and megahertz frequencies.

"Because they did not use electric motors."

Wooooo let's go back to 1827 for a moment and have a chat with Anyos Jedlik. Or maybe Andres Flocken in 1881. Let's see how they did electric vehicles.

Oh, lookie there, no SiC.