Something about the show I've noticed is that there doesn't seem to be any healing magic. Why do you think that is in-universe?

7175901
Lack of overt injuries due to the rating of the show is the likely out of universe excuse, that and to establish what level of medical technology they have naturally through the presence of hospitals and the like.

I’m not sure what the in universe explanation would be.

7175908

Perhaps either because healing magic has side effects (altering body parts, doing permanent DNA damage like real life chemo, shortening overall lifespan), or because healing is such a physically demanding school, they'd only use it in a worst case scenario (like a patient seconds away from death).

7175916
This would be an interesting story idea since healing magic is generally portrayed as light, wholly positive, and resembling miracles.

7175921

Nothing is without flaws. There are no solutions, only tradeoffs.

I can imagine healing being something very risky to use, and those who could use it would be respected and treasured to the point of possible worship.

Two examples leap to mind, one overt and the other subtle. When Apple Bloom chipped her tooth Zecora whipped up a potion that repaired it, and when Rainbow Dash broke her wing in "read it and weep" it was just a week or two before she was able to fly again.

We do know that healing magic stops short of being able to regenerate a missing wing or horn - Rainbow Dash had an artificial wing in the Sombra War alternate future and Tempest Shadow's horn was unrepairable. There was also a pony in a wheelchair in "Trade Ya!", presumably this indicates spinal damage is beyond pony healing magic.

7175901
Mi headcannon is that unicorn magic can't permanently transform other ponies. So no fixes - just temporary first aid, which a few gifted mages can apply in cases of injury more grievous than we ever saw in canon. (It works fine on non-magical creatures, but use for such was rare before Equestria's recent opening-up.)

Now to compensate for this , I also give ponies a subtle magical healing factor which accounts for swift recovery times and (together with another subtle magical effect which serves as a buffer for their internal organs) their cartoonish resilience. (In alicorns this magic, like all of theirs, is turned up to eleven, becoming strong enough to rapidly heal injuries and even overcome aging itself - a more subtle version means more magical ponies tend to live longer in general.)

Any mage can boost their own recovery at the cost of power - basically "MP to HP" - it's how Twilight went from a wheelchair to running and jumping in Feeling Pinkie Keen, and also why teleportation was off the cards. (Don't you just love it when you can patch two plot holes at once?) However boosting another ponies healing, or purging poison or disease, are rare and special magics that only a few ponies with the right talents can cast. Hence the need for modern medicine.

Of course, ponies aren't limited to relying on horn magic alone - indeed some of the greatest healers, like Meadowbrook, were non-unicorns who discovered the medicinal properties of the world around them.

7175901
The most healing magic we've seen, that isn't associated with a Deus ex machina like the Elements, are the potions and cures that Zecora brews. Not just for humans, believe in minor regeneration, like when she helped Apple Bloom's chipped tooth.

7175916
I recall how badly the wrong potion wrecked Rarity's ane, not even the Princess of Magic could fix it, or thought it should even be attempted.

In A Canterlot Wedding, Shining said "[Cadance]'s been using her magic to heal me". So it's a thing that is at least plausible, but of course that was Chrysalis in disguise.