Its enough of an incentive to repair them if their performance degrades when they are badly damaged.
If items become to damaged they don’t work very well, usually better to use another item.
main exception is magic items you mostly use for the enchantment.
This also show the main problem with this idea. If you use low level items like leather armor either because enchantments or just because of the style, you find that it have few hit point and might be broken in a hard fight.
just the restriction against field repair will make it far harder to keep equipment going, do not se any reason to make this harder.