Putting wizards in an economy

So, what would the theoretical average level of a wizard in a wizard region of a country be? They could perform some truly insane feats with their spells, and if the average citizen could achieve that level of mastery, spells like 'Fabricate' and 'Stone Shape' could yield a massive amount of products. For instance, with 'Fabricate,' an average caster could create up to 11 tons (a cube with a 5-foot side) of steel products. That's astonishing for an economy. Just imagine, ten Wizards capable of casting 5th-level spells could conjure 11 tons of steel with 'Create,'(Edit: i overlooked the fact that create doesn't actually create permanent materials, so the factory maintained just by a couple of wizards can't happen) then use 'Fabrication' to manufacture whatever is needed at that moment. In just 15 minutes, you'd have 110 tons of products materializing out of thin air. These are numbers that I doubt even modern factories could match.

But how could this be balanced on a country-wide scale? If you have something like 5-10 thousand wizards engaged in production, you don't even need traditional industrial capabilities for a country; just efficient means of distribution. Am I missing something here? If I were to make everyone in a kingdom capable of casting 1-3 level spells, would it diminish the uniqueness of wizards? Or should there simply not be that many wizards in the entire world? (Though the absence of wizards in a high fantasy setting might take away the excitement, such as magical academies and the like.)

Edit: Thanks everyone for the ideas, the general solution that i came up with, is that average spell level that most can cast is 2-3, and most actually economy breaking spells are difficult to learn because of an established monopoly.