Is the lack of bignums (more than int64) the real issue? JS has IEEE754 binary double so that's the same as in Python. Library code can be cross-compiled a num

Is the lack of bignums (more than int64) the real issue? JS has IEEE754 binary double so that's the same as in Python. Library code can be cross-compiled a number of ways, so I wonder whether the blocker is the lack of Pythonic long.