That's the current state but LLVM is adding new targets (like the newly added AVR target), while the AVR target in GCC is under threat of removal: https://www.bountysource.com/issues/84630749-avr-convert-the...
GCC still supports more architectures even if AVR support is removed.
> https://en.wikipedia.org/wiki/GNU_Compiler_Collection#Archit...
And the number of architectures by LLVM:
> https://en.wikipedia.org/wiki/LLVM#Back_ends
GCC supports vastly more targets.