Why would it not be impacted? You'd be breathing in unfiltered air, and that's the main method of transmission.
It would be impacted. You'd lose 100% of that benefit. But 100% is still not much.
What would even be the point then? That'd just be reduced to obstinate anti-maskers wearing lace 'masks.'
The mask still protects other people from transmission by you.
Anti-maskers wearing lace 'masks' does not protect other people.
They are completely different, and that is the main point of mask wearing for the general public - to protect each other by reducing the chance of ourselves transmitting it if we have it.
You're pretty much back at ubiquitous and widely available surgical style masks at that point.