Compressions only is taught for lay people because it increases the willingness of people to help. Compressions only certainly beats nothing. Compressions only is not taught in healthcare settings.
Personally, while I have Nu Masks in my vehicles, the odds are that I will not have a barrier device available outside of work. If you are someone I love, you will get breaths, if you are not, you will get compressions only (though if someone who loves you is present, I will give them instructions to provide breaths) because nothing can require me to risk my own safety to help someone else.