5th, mending & magic items, how do they lose their magic?

[Tetrasodium]

This spell repairs a single break or tear in an object
you touch, such as a broken chain link, two halves of
a broken key, a torn cloak, or a leaking wineskin. As
long as the break or tear is no larger than 1 foot in
any dimension, you mend it. leaving no trace of the
former damage.
This spell can physically repair a magic item
or construct, but the spell can’t restore magic to
such an object.

The mending cantrip says it can repair a damaged magic item but not restore magic to one. Other than magic items that explicitly say things like how they do things like crumble to dust when the last charge is used/convoluted circumstances like vecna bits have, are there any other circumstances where a magic item can become damaged in a way that strips the magic longer than it takes to walk out of an antimagic area?

[Cl0001]

It could always be through DM implemented options such as strong curses, or things of that nature

[Ninja_Prawn]

The mending cantrip says it can repair a damaged magic item but not restore magic to one. Other than magic items that explicitly say things like how they do things like crumble to dust when the last charge is used/convoluted circumstances like vecna bits have, are there any other circumstances where a magic item can become damaged in a way that strips the magic longer than it takes to walk out of an antimagic area?

I don't think there are any included in the RAW. That clause in Mending is probably intended specifically to target things that break when they expend their charges. There's plenty of scope for homebrewed things (or McGuffins) to be broken, depowered magical items though, and it'd take some of the adventure away if a quest to 'reforge this ancient sword' could be solved by a simple cantrip.

[Coffee_Dragon]

Player #1: Phew, it took 14 hours, but we finally wore down that iron golem to a pile of scrap metal.

Player #2: I'm Chaotic Neutral, so I cast mending on the pile of scrap metal just for the lolrandom.

DM: OK, it's back up to full HP I guess. Roll initiative.

Player #1: Nooooooo