It’s a sign of bad design to add something to the design later for one exception case. In this case, rain. A roof should be shaped to channel the water to where you want it. How many hours will a roof be on a house and during how many of those will it rain? Gutters are a poor solution to a problem that shouldn’t exist. They collect leaves and dirt, require installation, cleaning, and maintenance. I would hazard in my arid area that all this takes more time than the gutter gets rained on.
It seems the simplest solution is to adjust the roof joists, while a house is being built, to angle or channel the flow of water, snow, and ice. This doesn’t work for existing houses, but all news ones could avoid this excessive and unnecessary cost. A few inches here and there could save thousands of dollars and hours in the life of a house, which may be 20 to 100 or more years.