General anaesthesia is pretty much always dangerous, probably especially for children. Consciousness is still something that medical science doesn’t understand extremely well and there are far too many cases of not only adverse reactions to sedation but also people getting “locked in” and being conscious but not able to move their bodies or articulate that they can feel things.

https://www.aegisanesthesiapartners.com/anesthesia-risks-complications/

For some thats not an option due to health reasons. Especially for certain types of surgery.

Also small children shouldn't be under anesthesia so a distraction like this is a good idea.