Spell to-hit bonuses are based off of the spellcasting stat, not Dex.
Same as saving throw DCs
It'd be more fair to say that "most single target damage spells are ranged attack," and even then I'm not sure if that is true...
I was just coming back to fix that LoL. Tired. Still stands though with your qualification. "most
single target damage spells are ranged attack,"