Had your loved one tried ECT prior to ketamine infusion? Though its reputation has been sullied by popular culture, it is bar none the most efficacious treatment we have for treating severe and persistent depression, and its efficacy is well supported by decades of research and outcome tracking.
Where I totally agree with you is ECT. It is, with a bullet, the best-supported intervention for treatment-resistant depression, and it's not even close. It is an absolute tragedy that it has such an unfairly terrible reputation. Even before anesthesia was a universal element of ECT, it was never as bad as usually portrayed in popular culture.
My disdain comes from seeing people I'm close to repeatedly pushed towards those treatments by practitioners who, when asked to provide references supporting their endorsement supply anecdotes about past or current patients rather than DOIs. There are specific TMS protocols that appear to have some growing amount of evidence behind them, but ketamine still seems to be a wildly variable cash grab that requires further data before anything can be said about its efficacy.