Cleaning and filing the contacts may get you a little more life out of the switch, but it’s been my experience, that once they are worn out, it makes the most sense to replace the switch.
Things to consider are the size of your pressure tank and whether it is set up properly. A small tank is fine if you’re not using a lot of water, but with a big family and a lot water consumption, a bigger tank is definitely better. The pump will not cycle on and off as much. That will save your switch contacts, you will save on electricity and in total life of the pump.