I absolutely agree with Argentdawn. The "softcap" on crafting should come from the attention span of the player. Powerful equipment should take effort to create - it should be a process, not a button click. By doing so, there will naturally be a limit because people simply won't want/ have the capacity to spam make items.
Well the cap in crafting I imagine is going to come from the fact that resources aren't globally available. If you live in a metro that produces lumber you're going to have to import iron to make a sword. That means travel time (as fast travel is a limited thing), getting to the foreign place with iron, purchasing it at a reasonable price, setting up a caravan, and then guarding it all the way back to your city.
Jahlon asked Steven about this on discord and this is what Steven had to say about it.