Maybe machine learning models technically fit the definition of "algorithm" but it suits them very poorly. An algorithm is traditionally a set of instructions written by someone, with connotations of being high level, fully understood conceptually, akin to a mathematical formula.

A machine learning model is a soup of numbers that maybe does something approximately like what the people training it wanted it to do, using arbitrary logic nobody can expect to follow. "Algorithm" is not a great word to describe that.