It's not the switch, its the driver side window motor itself. Like anything else thats mechanical, it wears out over time and the driver side window is always the most used in any vehicle.

Pull the door panel, then the motor, and clean the apature and the inside of the housing. Theres tons of shavings from the magnets built up in there. Itll run like a champ afterward. You might wanna do the frint passenger too while youre at it.