Actually, I support this. No one but a vet should administer the sedative, which is usually IV, and usually in fairly heavy doses, to enable the horse to tolerate the power tools most are using now in their mouth.
If they can do it without sedatives, then more power to them. Most though, can’t do as thorough a job.
As for how horses survived without this in the wild... well, in the wild, success is surviving long enough to breed. In domestication, we are keeping horses, and expecting them to be fit and healthy long into their 20s.
Mine is 28, and is still my riding horse.
Also not to be ignored, is that there is some amount amount of ‘survival of the fittest’ at work in the wild, and not so much in domestication. The uneven wear that is the problem is a problem because of imperfect bites. Those horses with really bad bites would die in the wild, in domestication, they can be easily floated, and bred.
Continuing:
“Equine dentistry” is a completely unregulated field. There is no accreditation or licensing of equine dentists. They are not in any way equivalent to human dentists. They are more like farriers. It’s a trade, and the amount of training really varies. Some went to good schools, some went to weekend crash courses, some may have just apprenticed awhile and hung out a shingle and called themselves a ‘dentist’. They’re not. They’re not doctors.