1. It has a higher bandgap energy than silicon, which means it can tolerate more heat without breaking down. It also means the junctions can be physically smaller.
2. Smaller junctions mean the transistors can switch faster, which means less time spent in the linear region, which means they generate less waste heat than silicon transistors.
3. SiC also has lower ON resistance, which means less waste heat still.
4. SiC conducts heat better than silicon, so removing its [lesser] waste heat is easier and requires a smaller heat sink apparatus.
All of this makes SiC a fantastic technology for power electronics. (It's less important for signal electronics, but even signal electronics waste small amounts of power so reducing that further is still relevant.)
For EVs, SiC inverters mean less mass for an EV to carry around. Less mass per se doesn't matter as much as you might think for an EV because with regenerative braking you get back some of your acceleration energy when you decelerate. However, air resistance matters enormously in an EV because you can't get back the energy you lost pushing the car through the air. And "less mass" also means "smaller" and "smaller" means "more opportunities to make the car aerodynamically efficient."