Home pizza hobbiest here. I use low-moisture part-skim pre-shredded mozz, but put it on the pie frozen. As long as there's not too much grease from the toppings I rarely get problems with the cheese splitting.

The places I worked had floor mixers, running on 3-phase, that could do 50kg of dough at a time. They have mesh guards that lower into place, without which they won’t run. Because they will pull your entire arm in and break each bone in a dozen places before you can even blink. I have never, ever seen one with an external powered attachment drive like a kitchenaid, or at least never seen it used. A shredder that powerful would almost certainly be illegal under our workplace safety laws (Australia), it would probably rip someone’s face off if their hair got caught.

Besides that, it is still labour cost and time to do. When that person could instead be doing something better. The highest end pizza place I worked at would cook everything in wood-fired ovens. Pre-shred was used on the cheaper pizzas. It was used as a base on pizzas that had things like pulled pork and shredded lamb too. We had real, buffalo mozzarella on some, as well as bocconcini & fresh, local goat’s cheese. We’d also go through 4-5 full hotel pans of it on a Friday and Saturday night. Would make our own pasta in house every day too. There Was Not The Time. Yet it never stopped us packing a 120 top three times over with dozens of orders for takeout per hour every weekend. ¯\_(ツ)_/¯

Also, I’ve never seen anything other than low moisture mozzarella sold shredded. Maybe that’s just me.

I don’t know, I live in Australia, maybe Americans are just that whingey about it? But outside of the cheapest supermarket home brands, most shredded cheese here hasn’t got caking agents. As far as I can tell, people buy it just bloody fine mate. Imagine being this stuck up about shitty, horrible cheese.