Yeah, that's the honest take. Healing's a support tool, not a carry spell, and Skyrim's design just doesn't incentivize it the way some other RPGs do. Enemy scaling is brutal enough that by level 35 you're already running into stuff that tanks healing faster than you can cast it.
One thing the previous reply didn't mention though - if you're gonna commit to Restoration, grab the perk that reduces spell cost. Healing spells are expensive for what they do, and cutting that cost down makes it way less painful to spam them in a pinch. Makes a real difference when you're juggling Magicka for offense and defense.
Also, and this might sound weird, but Restoration actually shines more if you're NOT playing pure solo. Followers are dumb as hell but they die easy, so keeping them alive with group heals (the perk mentioned above) actually feels useful. On a solo run? Yeah, potions are faster and more reliable. But if you're running with a melee companion, Restoration stops feeling completely dead weight.
The Necromage thing is legit though. That 25% magic boost is stupid good and honestly makes the whole mage build feel less anemic. Only catch is you have to deal with the vampire weaknesses - fire damage sucks, Dawnguard NPCs get weird about it, and you're stuck doing the sun thing. Totally doable on PC or if you don't mind the inconvenience.
tbh if you want Restoration to actually matter, you kinda have to accept it's a "keep yourself and allies topped off" tool, not a "tank massive damage" tool. Different playstyle entirely.