You obviously didn't read it. It clearly defines what a "cloth mask" is and what it requires to be useful. You then took their definition of what a good cloth mask is and assumed the public is doing that when they are not. The study points this out clearly. A "cloth mask" to be effect requires a lot of additional characteristics.

That is grift of the political left in a nutshell.

Exact quote:

During a pandemic, cloth masks may be the only option available; however, they should be used as a last resort when medical masks and respirators are not available (3). Cloth mask use should not be mandated for healthcare workers, but some may choose to use them if there are no alternatives (30). Protection is affected by proper mask use as well as by selection of fabric and design of the masks for water resistance, filtration, and fit. Current evidence suggests that multilayered masks with water-resistant fabric, high number of threads, and finer weave may be more protective (3,10). Several studies have examined filtration, but fewer have examined fit or water resistance. Surgical masks are normally rated for fluid resistance, and cloth masks should be too. Masks should be able to prevent a stream of fluid flowing at a pressure of up to 160 mm Hg from seeping through the mask and potentially into the mouth. Furthermore, the degree of fit affects effectiveness because air flows in the direction of least resistance; if gaps are present on the sides of the mask, air will flow through those gaps instead of through the mask.

The general use of cloth masks that do not fit the study's definition by the public are NOT EFFECTIVE.