What is the most common reason a sump pump fails 6

https://remote-wiki.win/index.php/Why_Sump_Pumps_Fail:_Lessons_from_Gateway_Water_%26_Mold

The most common reason a sump pump fails is a stuck or clogged float switch. Over time, debris, grease, or mineral buildup can jam the float, preventing it from rising with the water level, so the pump never kicks on when it should. A piece of gravel or a rusted bracket can also snag the float arm. Without that simple mechanical trigger working freely, the pump sits idle until the basement floods, often catching homeowners completely off guard during a heavy rain.