probably worth it for mt fuji and nikko
I did a quick search on hyperdia e.g. from Tokyo station
-Tokyo–>Kawaguchiko one way ¥ 2,630, 177min
-Tokyo–>Nikko one way ¥ 5,580 107min
-Tokyo–>Kamakura one way is much cheaper ¥ 920 52min
For mt fuji/nikko, it might be important to reserve the tickets immediately after purchasing the tokyo wide pass.
For mt fuji, Kawaguchiko might be one of few options using the tokyo wide pass (and I recommend going on a clear day). Otherwise alternatives are the convenient bus day trips, or go to Hakone using hakone free pass (private train line).