Sage and SymPy are not direct competitors. Sage is a Python interface to other math software. SymPy is closer to one of Sage's dependencies, Maxima. On the "mot

Sage and SymPy are not direct competitors. Sage is a Python interface to other math software. SymPy is closer to one of Sage's dependencies, Maxima. On the "motivation" page you linked, they actually state that they're working toward making SymPy a drop-in replacement for Maxima in Sage.