mev

Not sure I fully understand the question in context of a "fitness" or "road cyclist". I assume for these two categories, the most common situation is that they are home. So a rest day is a situation where they are home but not riding.

I assume for a "long distance touring cyclist", they are not at home. In this category, the most common situation is they are not at home. A rest day is one where you are still out of your home situation but not riding that day.

Based on my experience, if I were to guess, I would expect to have more "rest days"/"non-cycling days" when you are at home. They might be days you are actually chosing to rest and not ride. They might also be days you simply are doing something else, e.g. doing other errands, working, visiting others or anything in a list of many things you I more easily do at home than when I am on the road. So my best guess at the answer is "no, someone at home might take more non-cycling days than someone on a long-distance tour in part".

However, if we put aside the comparison aspects of your question, there is a separate question of how often do touring cyclists take a rest day and under what circumstances. For me the answer really depends on the overall length of the tour:
- When my trip duration is short e.g. four days or less; then no I don't expect to take a rest day.
- When my trip duration is a week or two; then I am more likely to put in a "contingency day" to deal with unexpected things that come up, e.g. inclement weather, mechanical issues, interesting tourist opportunities. Sometimes the contingency day gets saved to the end point but sometimes I might use it along the way.
- When my trip duration is longer, say a month to many months - then I have allowed extra days along the way. These have been used in a variety of ways on some of my longer tours, e.g.
* Cycling the outside of Australia for eight months, I took some for tourist highlights e.g. Uluru or the Bungles or ... other places I might not see again
* Cycling six months in USA last year, I took some for extremes of weather (e.g. heat warning in Iowa, smoke in Illinois, rain in South Dakota, wind in Washington)
* Cycling across Russia, we would travel/camp for 7-10 days between larger cities and then when we reached a city we would stay for two nights in a hotel and get a chance to do laundry, refresh, etc.
* Cycling across the Americas for 18-months, I took a break or two for weather, but also along the way to attend language school, to fly back and file my taxes, etc.

Sometime rather than a specific rest day, I will use that contingency time instead to make a shorter ride. A good example was last year I was traveling through Nebraska in August when an abnormal high "heat dome" event happened. Mornings were still comfortable but heat/humidity in the afternoons was much higher. So I took ~6 days to cycle what I otherwise would have spent ~4 days riding and took my afternoons off.