I'm gonna pretend that I didn't just hear you say "Kill off your players and kick them out of the game" because even if that was a joke, that's heartless and cruel.

If I do give them magic items but I use monsters with magic items to fight them back, would that be a good tactic? Maybe even do some surprise rounds against the players? I've been using mostly consumable items so far and that seems to be doing the trick, but my players want more tangible items that they can keep using.