Why should people start using high-filtration masks like N95s and KN95s as their go-to, everyday masks rather than cloth ones?
The key reason is that transmission of the coronavirus is primarily through aerosols, which float around in the air — you inhale them — and are not filtered well by cloth masks. You really need melt-blown polypropylene, which you find in surgical masks and N95s, to stop these small particles.

So the materials used to make these masks make them better equipped to filter out the virus?
Yeah. The material is basically melt-blown polymers, like polypropylene, which form this complex sort of webbing which is then electrostatically charged, and that pulls the particles in when you’re inhaling and exhaling. Cloth masks are often just woven thread and other materials that don’t have that design. Cloth masks don’t provide great source control, either. The CDC is now letting people who test positive for COVID-19 stop isolating after five days and then wear a mask for five days. It would have been ideal for them to also recommend that be a better mask.