The big spectacular eruptions are actually due to gas rich magma in fractures in the Izu arc being squeezed horizontally N. along the arc by differential convergence (fastest in the S.) eventially arriving at a volcano when they hit a segment boundary transform fault & can go no further.
News indicates that Fuji area may now inhibit travel of magma rich fractures with Hakone or Izu Tobu a more likely target for eruption of Izu arc magma rich fractures.
Fuji does have a high level magma chamber & this indicates that it may now be subject to the "Zit" effect, involving emergence of main deep sector magma of the high level magma chamber forming a dome & flow on the cone at low gas content.
Izu arc is now backing up against the japan alps megathrust and this has now recently prevented backarc spreading resulting in rebound/long duration mercalli X (r/lx) relaxing the crust at Fuji, Hakone, and Izu Tobu in 1703 with a small runout, resulting in a short recompression interval time and a 2nd R/lx in 1923.
Fuji in this tectonic regime is now a backarc volcano with as a result only rare input of gas rich magma immediately after r/lx when the crust immediatelu S of the volcano is relaxed enough to enable magma transfer.
Izu tobu has been active recently.
Have a nice day: Ag