That'a true and Julia might be a solution but I don't see the adoption happening anytime soon.

But this particular problem (per row computation) have different options to tackle now in hep-python ecosystem. One approach is to leverage array programming with NumPy to vectorize operations as much as possible. By operating on entire arrays rather than looping over individual elements, significant speedups can often be achieved.

Another possibility is to use a library like Awkward Array, which is designed to work with nested, variable-sized data structures. Awkward Array integrates well with uproot and provides a powerful and flexible framework for performing fast computations on i.e jagged arrays.