I would also point out that dialysis, chemotherapy, etc are also quite expensive, time consuming, and difficult to scale. We still consider them valid, life-saving treatments.

Ketamine is not your traditional SSRI. You're making the same error as the other poster in grouping all "antidepressants" under the same umbrella, which is particularly egregious when discussing ketamine.

I lack training in psychopharmacology or neuroscience and thus my interpretation of the research is that of a layperson, but my understanding from talking with psychiatrists on the matter is that it is unlikely that ketamine will become a frontline treatment but its mechanism of action will be explored and lead to the development of new drugs that activate the same pathways in the brain but lack or have lessened anesthetic effect.

This is a horribly ignorant statement. Ketamine therapy is in no way comparable to widespread opioid prescription in risk. You are once again comparing drugs with entirely different mechanisms of action.