You got that right, it's 1d8+8 per level of the heal spell used with the 2 action version up to 30ft. So level 2 heal is 2d9+16 and a level 10 heal is 10d8+80!
The heal spell is actually good at healing now in PF2, and it replaced cure light wounds form previous editions and the Heal spell of old.
Keep in mind costing 2 actions is kind of steep, when you only have 3 actions per turn. And it's also one time healing (per spell slot). And if you're not using on level spell slots the effective relevance decreases (ratio of relative amount healed to total HP).
So yeah, it should be good.
Also remember, someone trained in Medicine can use Battle Medicine to restore HP as 1 action activity that restores 2d8 hp (trained) up to 4d8+50 depending on your proficiency level and the DC you target. Now this is touch range, so you would generally need to move next to your ally so you'll likely spend 2 actions.
Anyways, overall point here is that healing is actually good in this edition, and while it (IMO) still shouldn't be the main focus of a character it is absolutely competitive in terms of outcomes compared to dealing damage or inflicting conditions on the enemy, as it should be, to actually make people want to do it in combat.
Another point of comparison, being able to heal 1d8+8 (average 12.5 hp) for a spell slot isn't actually that good, when you consider that it's basically the amount of damage an enemy could inflict in 1 to 2 hits.
Basically if an enemy is focusing on your friend, healing them is basically just a stalemate situation, but you'll run out of spell slots before the enemy will stop swinging (unless someone else gets involved and takes out the enemy).