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.