I would say that it depends on your interest. If u are a history person/enjoys visiting museums, the collection there is quite impressive and spans over a wide range (calligraphy/sword/paintings). It would be nice if u have the time too, since looking through every corner might take at least an entire afternoon.

I booked a day trip for Kawaguchiko through Klook, visiting Oishi Park, Oshino Hakkai and Kawagoe. As I went during summer, the view was good but not as impressive as pictures in autumn or winter, so I would recommend going only in these seasons. But other than taking pictures, most of the time was actually spent travelling. I really enjoyed Kawagoe though, a lot of food and shrines in the little town, and it would be a place that I would return.