There is no way that you are not having your intake of air restricted by putting a piece of cloth or fabric over your face. For the average person it probably doesn't make a difference in the way their body or mind works. But small changes can and do make a huge difference in people who are not neurotypical, or have breathing issues due to their sinuses.
That is my assertion as well. The simple physics of it require that filtering air effectively will reduce the air-for-effort. If you're not experiencing this, you're pulling air from around the sides of your mask.
(Note that not noticing it is not the same as not experiencing it.)
