>>22535519>Or is it the lack of powerful super effective stab?This. 135 would be nothing to scoff at if it had anything more reliable than Tri-Attack to punch through anything BoltBeam doesn't hit super-effectively. I mean, Porygon-Z packs a punch, but it's almost impossible for it to take down anything with passable Special Bulk. And it's because of its lack of powerful, reliable coverage (STAB or otherwise) that it's hard to succeed locked into one move.
Z just doesn't have the killing power, despite its great offensive stats.