Oil pumps in a vehicles engine are designed to last the life of the vehicle or at least the life of the engine which is around 300,000 to 500,000 miles.
However sometimes an oil pump can fail although rare and when it does the engine gets starved of essential oil that it needs for lubrication.
When the engine cannot get any oil then the bearings will eventually seize and the valves and lifters will begin clattering.
Most commonly an oil pump will fail due to lack of lubrication from the engine oil in the pan being sucked through the pump.
That can happen when you run the engine too low on engine oil and when the engine oil is too low the oil pumps sump won't be submersed fully in oil to keep the engine oil pump primed.
That can lead to the gears in the oil pump wearing out which is what could cause the oil pump to fail.
Oil pressure drops can happen sometimes from a bad oil pump but other times it's caused by low engine oil level, clogged fuel filter, worn engine bearings etc.