To say they do nothing is stupid.
Of course they do.
Every spit when you talk, feel a mist when you sneeze?
Any barrier even a hand, or a shield will stop that.
So, no it's not absolute. Few tghings are.
It's actually not even very good, but yes it will help.
Does it help enough to matter?
Do they increase germ transfer more than they help?
Welllll, now there are some good questions
that won't be clearly answered.
