Restoration in Oblivion is actually way more useful than it gets credit for, and it's not a trap at all - the reputation problem mostly comes from people comparing it to Skyrim's healing spells, which are genuinely boring. Oblivion's Restoration is different.
The thing is, Restoration scales off your Willpower attribute, not Magicka pool directly, so if you're already deep into Alteration you might want to respec your attributes at a shrine before you get too far. But the skill itself has some genuinely good utility spells that aren't just "heal yourself." Cure Poison, Cure Disease, Restore Attribute - those last ones are critical because stat damage is way more punishing in Oblivion than Skyrim. Enemies can permanently drain your Strength or Intelligence mid-fight if you're not careful, and Restoration is the only way to fix it without hunting down rare potions or waiting for a shrine.
Plus there's the Restoration loop stuff if you want to get into that, but that's more of an exploit thing.
At level 12 you're not locked into anything yet honestly. You could grab a few Restoration spells from a vendor and test them out without committing hard. If you hate it, the skill barely costs anything to level compared to Alteration. I'd say it's worth having at least a few basic spells on hand, especially Cure Disease - you'll thank yourself later.