You don't compile bytecode, you compile to byte code
I can't tell if you're just being obtuse, but: the developer compiles shader language to bytecode, and the graphics driver compiles bytecode to GPU native-code. Both of these stages qualify as compilation. (They're both level-reducing language-transformations.)
The entire point is that byte code is interpreted at runtime.
No. There's no way in hell that anyone's seriously suggesting running graphics code in an interpreter. Again, it will be compiled by the graphics driver. (We could call this 'JIT compilation', but this term doesn't seem to have caught on in the context of graphics.)
building native execution of the bytecode would be fastest
Why not call this what it is? It's compilation.
Especially since the bytecode is supposed to be hardware neutral, it is the compilation from bytecode that will have to do the aggresive optimizations to adapt to the target architecture.
You can have very simple bytecode that doesn't need much processing, and while technically compilation is really compiled, but that wouldn't make sense here.