I have brought one along when I plan to go to a store in the middle of the ride(ice cream stop with the family). I dont bring one on every ride though. They arent required by the state/towns where I am and most stores ask but dont require them to be worn. If I am on a ride, the only place I would go to is a gas station where its maybe 40/60 for wearing masks anyways.
I plan for a lot when cycling, but have to draw an arbitrary line somewhere. I for sure would have one if I was in an area that requires them in any/all stores.