I dont really get why lockpicks need to break - at all.

Its supposed to be a kind of a resource that spends over time and that you need to invest into... but i really dont see whats the overall purpose or point of it.

It would all be better if lockpicking was just skill related and you get one set of lockpicks (maybe find a few better versions along the way) - and use them throughout the game.
Where lockpick quality would function as a bonus to your lockpicking skill.