Simplest point - if you want to craft an item, you need a recipe. That has to be found in-game. If the GM doesn't place the recipe in game, you can't make the item, period. On top of that, all magic items require special ingredients they also have to find in-game. So this is completely in the GM's control.
My artificer has yet to make a single magic item.
In this way, you can keep crafting for things like healing potions and spell scrolls, but not have extra items crop up.
The smart GM, however, will allow crafting - and instead of giving the party so many items, makes many of the items they'd give as recipes instead, so that the Artificer has to make the things for the party. Keeps the balance while allowing the character to exercise their shtick.