For evidence supporting mask use, see Respiratory Protection Works.
There is some nuance here, both depending both on what is meant by “don’t work” and also by what is meant by a mask. A typical cloth or surgical mask doesn’t provide much protection for the wearer, but they are useful at helping contain aerosolized particles. A respirator on the other hand does provide protection for the wearer, such as a N-95. Their effectiveness also depends on how good of a seal is formed on the face and why fit testing is conducted for healthcare settings. Respirators that use ear loops will not form as good of a seal as elastic head straps.
Most of the misinformation that has been spread is due to not understanding those two basic questions. In addition, those who write articles discrediting respiratory protection often don’t have the skills to identify flawed study designs.
Denial and Misinformation/Lies
Below are some links to articles by some of the larger misinformation pureyors. There are separate pages for each organization and I’ve listed the articles I’ve responded to below. To find the rebuttals, click the name of the organization.
Universal Masking in Health Care Settings Is Unnecessary
Long Covid Could be Mask Induced Exhaustion Syndrome (MIES)
How Zeynep Tufekci and Jeremy Howard Masked America
