Steel covers Psychic's weaknesses, making them hit neutral. Psychic covers Steel's Fighting weakness. Levitate covers Steel's Ground weakness. And my tendency to not use Fire types covers Steel's Fire weakness.
It was especially brutal in Diamond/Pearl when the Fire types in game were Ponyta and Chimchar. Your best non-fire bet was Skuntank. --- "Gary was here. Ash is a loser!" = Greatest Tramp Stamp Ever