Here's a hot take: maybe they shouldn't have had magic items that granted bonuses to hit or AC to mess with bounded accuracy. No stat increasing (or really, stat setting) items, no +1 swords or armor, just items that grant new abilities to their users.
I'm on the fence about weapons that add damage dice; I think these are ok, even though I know the game is actually balanced around damage vs. hit points. But we do have items that don't have bonuses that still do stuff, like Adamantine armor, Brooms of Flying, Wands and Staves that grant extra spells, and the like.
I really think the only reason we have +1 magic items is because....well....someone would say it doesn't feel like D&D if we didn't.