This is interesting but I'm not sure I fully understand, as I'm not 5e-savvy and don't pay close attention to the numbers in the game. Are you saying that because spells with attack rolls are mitigated by AC, they've benefitted from AC reductions, whereas AC has no impact on spells with saving throws (instead it'll be DEX or WIS or whatever the saving throw is based on) they get no benefit from AC reduction but the damage they do is less proportionally due to higher HP?
I confess that I tend to focus on attack roll spells but that's been more because I seem to waste fewer turns by failing to do damage than with saving throw ones, but that's to do with the probability of hitting rather than the amount of damage, and I think your point is about the latter for saving throw spells? I think I need to pay attention to the numbers after all and understand what factors lead to my spells connecting or not, though I don't think the game is great at educating me about this or at least I can't always work it out from the tooltips.
