Besides vehicles that need to replaced if you don't want to deal with the drop in functionality or like me feel a need to have " + + " vehicle condition for no other reason than uniformity
Your clothing and equipment can be repaired indefinitely if it provides the information that it can be repaired and what resources you need to repair it. Items you cannot repair will specifically say so in description.
And guns have another level of maintenance in the fouling system but reasonably shouldn't be a problem unless you use black powder ammunition or use a gun as a primary weapon for a long time.
Items when properly maintained can work with no lasting performance defects
Also need to also be aware that electronic things can be broken and at that point if it says "broken" then it is beyond reasonable repair and can be dissassembled for parts - broken can be achieved by close proximity to electrical current and emp attacks and is more easily affected if an item is in a conductive pocket or if you dive into deep water as far as I know.