Metagross only had 2 weaknesses in gen 5, fire and ground. Despite this, he was almost always completely outclassed by Jirachi due to being slower and lacking any sort of reliable recovery. Steel losing its resistances to dark and ghost really, really hurt it defensively. For the record, metagross was only OK in OU back in gen 5. He was ranked B tier on the viability ranking(compared to A+ Jirachi). Nowadays, he's just a slow stealth rocker. There are better physically offensive steel types, suicide leads, and much MUCH better bulky steel types.
