Unfortunately the 70% price rise on the JR pass back in 2023 made it much less likely to be economic for most people compared to just buying tickets as you go, even for trips that visit more than one city. Last time I was there I did a loop up from Tokyo to Hokkaido and back by rail, and it was still cheaper to buy individual tickets. (There are obviously still some itineraries where it works out cheaper, but it's much less of an "obviously good idea for most people" than it was back before 2023.)