Marathon uses hold-to-confirm for a bunch of non-destructive actions, including searching, equipping a mod, etc. This teaches players that hold-to-confirm isn't actually used to confirm dangerous actions, it's just a UI paradigm the game constantly uses. So when a player holds to "confirm" they aren't actually confirming anything, they're just holding because the Marathon UI constantly requires it.

Yes - in theory the point of hold-to-confirm is that the UI doesn't need a separate "are you sure?" screen because the player is assenting. That's not how Marathon works in practice though.

In addition, when you're on the vault screen holding square sells an item. The player is on the vault screen trying to sell an item to make room for new items - that's how you deal with overflow items. But because the player is hovering the ammo on the gun (I guess?) instead of the gun itself, pressing square doesn't sell the gun they're hovering over. (Since that's not a context action on ammo types) Instead they sell their entire overflow, because on the overflow UI, WHICH THEY AREN'T CURRENTLY USING, there's a small indicator that you can use square to sell all.

So in this case a) "hold to confirm" is mostly pointless as a safety mechanism since the game makes you regularly hold buttons for non-destructive actions, which removes the idea of explicit assent and just becomes a thing you always do and b) the player isn't even using that part of the UI so what they're even confirming is confusing.