Rather than using a better data structure from the start (class vis-a-vis dictionaries), why not move to a better Python implementation (PyPy vis-a-vis CPython)

Rather than using a better data structure from the start (class vis-a-vis dictionaries), why not move to a better Python implementation (PyPy vis-a-vis CPython)? When I need a data structure, I look for one that is a natural fit to the problem. Perhaps everything is implemented as a hash table in a certain language (not taking names here :)) but would I replace every data structure with a hash table for efficiency? That would be Premature Optimisation. I would recommend to code in idiomatic Python as much as possible (in this case, use a tuple for Point). Primarily because it is easy for other fellow programmers and your future self to understand. Performance optimisations are best done by the compiler for a reason, it is usually a one-way path that affects readability.