My wife and I discovered the miraculous qualities of merino when we did the Camino de Santiago in Spain a few years ago. It’s comfortable even in hot weather (35ºC plus), lightweight, incredibly easy to wash and dry (it dries in a snap), and, the big secret, virtually stink proof. It really is. So maybe if you have had a hard day’s hiking you might forgo the laundry….
Polo merinos look smart enough for the evening meals too.
Only downside is that is that merino is a bit fragile compared to cotton or synthetics, but I live with that. I bought these for another camino later this year.