Disposable surgical masks are not that hard to wear for hours on end. You get used to it. Medical staff do it all day long. It’s the washable cloth ones that are more difficult, and IMO, often the source of most of the complaints. Try it at home and see. In any event, your vaccinations are the primary defense against Covid, and the surgical masking is to protect others, as well as to comply with airline rules.

Since it’s Flyertalk, I’ve got to ask. What domestic flights take 15 hours in the US? Or are you outside CONUS?