What is incorrect about his post? Maybe you misunderstood the content. Virus are indeed very, very tiny. Cloth masks do not work against them. And, yes, wearing a mask for prolonged time can have deleterious effects.
What comes out of the body are NOT "very very tiny" virus particles...those emissions are large drops of salt water with virus particles embedded, and masks "do" stop them.
Even when those saline droplets completely evaporate off all water, they are still far larger than individual virus particles.
I "misunderstood" nothing.