Automatic kernel fusion (compilation) is a very active field, and most major frameworks support some easy-to-use compilation (e.g. jax's jit, or torch.compile which iirc uses openai's triton under the hood). Often you can still do better than the compiler by writing fused kernels yourself (either in cuda c++ or in something like triton (python which compiles down to cuda) but compilers are getting pretty good.

edit: not sure why op is getting downvotes, this is a very reasonable question imo; maybe the characterization of kernel compilation as "AI" vs. just "software"?