Possibly more humiliating to see an opponent mind be completely wiped out, possibly living the rest of their lives as a vegetable and to need the care of someone. When one is killed for their ideas they become a martyr of sorts.
https://en.wikipedia.org/wiki/Scopolamine#Use_in_crime
The estimate of 50k criminal cases involving scopolamine in Columbia makes it sound mainstream.
Nevertheless: > [...] on the World Health Organization's List of Essential Medicines.
Well I don't know. But having tried drugs like Ambien which is a prescribed sleep medicine and it kind of completely removing all filters far, far more than alcohol would when not going to sleep immediately after and then not remembering anything the next day at all I found it plausible for there to exist really scary drugs like that, which would congitively affect you and your personality.