SiC has a lower electron mobility than GaN (and, in fact, even Silicon), so in identical scenarios it can't switch as quickly as GaN chips.
SiC has significantly higher thermal conduction than both Si or GaN, though, which makes it more suitable for cases where you need a ton of thermal capacity (inverters for EVs, for instance).
Both technologies are in their infancy, though. You can get better performance out of either by improving the process technology aspect, so it's hard to say one will ultimately be better than the other. Given the electron mobility though, it seems GaN will ultimately win for devices that aren't thermally limited.
SiC has significantly higher thermal conduction than both Si or GaN, though, which makes it more suitable for cases where you need a ton of thermal capacity (inverters for EVs, for instance).
Both technologies are in their infancy, though. You can get better performance out of either by improving the process technology aspect, so it's hard to say one will ultimately be better than the other. Given the electron mobility though, it seems GaN will ultimately win for devices that aren't thermally limited.