There have been already studies on the usefulness of masks.
You protect others while wearing them and yourself.
No drawback or slight discomfort?
Slight discomfort is no drawback, compared to the risk of a potentially deadly disease.
If spit was the problem this disease wouldn't be so contageous, but I doubt anybody can be so ignorant after more than year of this pandemic.
old guy with asthma?
I don't know how it is in other countries, but you can get an exception for wearing a mask on medical grounds, but the asthmatic colleague I have preferes to wear his mask since he knew that getting the virus could be a death sentence for him.
a concept that is foreign
It would be fine if your decision only affected you. You can drink yourself to death anytime you want. But your decision also potentially others. People who can not get a vaccination, family members and so on. I suppose this is the difference between you and me. The prospect that I could give this virus to others because I feel slight discomfort while wearing masks horrifies me. It is not something I'd want to take responsibility for when St. Peter calls my name.