Thomas Shey
Legend
The only argument I can see for dealing no damage on a save is that flaming sphere requires only an action to Sustain it (and move it), so can you ram things with your sphere while casting spells or doing other things.
The sorcerer in my game used flaming sphere to good effect. I expect it let’s problems for repertoire-based casters because you don’t have to dedicate the slot up front. I can see why it might feel like a poor choice for a prepared caster like a wizard.
Its an argument. But at that point you absolutely need to cast it early, because its only going to really pay for its downsides over time, and one of the notable things about PF2e is that the majority of combats don't last too many rounds (I'm wanting to say I've rarely seen them go beyond five).