> Since the register size is fixed there is no way to scale the ISA to new levels of hardware parallelism without adding new instructions and registers.

I look at SIMD as the same idea as any other aspect of the x86 instruction set. If you are directly interacting with it, you should probably have a good reason to be.

I primarily interact with these primitives via types like Vector<T> in .NET's System.Numerics namespace. With the appropriate level of abstraction, you no longer have to worry about how wide the underlying architecture is, or if it even supports SIMD at all.

I'd prefer to let someone who is paid a very fat salary by a F100 spend their full time job worrying about how to emit SIMD instructions for my program source.