Regarding historical or traditional training practices:
Within physical culture, old practices or concepts aren’t necessarily good or better than modern ones just because they’ve been around awhile. There is belief in martial arts circles, especially in “traditional” groups, that something which has been passed down for decades is unquestionably valuable, or even superior to modern evidence-based understandings. A common defense is “do you think technique x would still be around it if it wasn’t battle tested?” Another is “look at practitioner x- if it worked for him, and he had no fancy research.”
The plain and unglamorous truth is that sometimes techniques or training practices got passed down simply because no one knew any better, or it fulfilled a cultural function (particularly in Confucian-influenced societies) or because they maintained a certain personal prestige or power structure within a group. A technique may have never actually been used in a fight; a conditioning activity may routinely cause joint damage that actually weakens a student over time, but the status of the originator serves to enshrine it. Old can be good; old is not automatically good.