People adjust the masks often. They aren't very comfortable and it's unpleasant to wear them for long, they can feel itchy which promotes face touching. The seal around your mouth probably won't be great unless you've been fit-tested as well so you'll be tempted to touch there.
All of those sound like issues that would be fixed by using better masks, that fit snugly and feel comfortable, and can be washed or even medicated, instead of the very cheap disposables.
What?? How do you figure that?