Even then, if you're familiar with NumPy it's pretty easy to switch to Jax's NumPy API, and then you can easily jit in Python as well.

As long as someone else does the porting and maintains the compatability between both subecosystems of thoose who prefer using Jax and thoose who prefer depending on the NumPy. Also not having zero overhead structs that one can in an array handicaps types of performance codes one can write.