I've yet to find an item that I'd ban. I LIKE magic items. And ive been known to hand out things that are way more broken than anything thats been printed. Often simply to see what the players will do with it....
But one doesn't normally get to simply go shopping for magic items when I DM. Yes, specific items can be obtained. But it's handled in-play & takes time & effort + resources. So I don't have players simply spending X GP between sessions & showing up with "surprises".
Crafting is similar. Though my general stance on crafting is that if you've got time to do this, then I'm not running a good enough adventure. Unless what your crafting is specifically a plot required item.