As a rule of thumb, a superhuman has to be at least as destructive as an ABC weapon themselves, before deploying ABC weapons becomes worthwhile. Because ABC weapons represent fairly extreme level of force, there is actually fairly large sweet spot where a superhuman is both:

1) largely immune to conventional weaponry, up to and including high explosives and fuel-air bombs with explosions measured in tons of TNT.

2) not causing as much collateral damage as a tactical nuke measured in kilotons of TNT.

Also keep in mind that a lot of natural disasters, such as hurricanes, earthquakes, tidal waves, volcanic eruptions, solar flares etc. are vastly more energetic than even the most powerful fusion explosions measured in dozens of megatons of TNT. So if a superhuman is powerful enough to cause natural disasters, it starts to become likely that even ABC weapons are not enough gun.