A 'hundred' years ago the guys who thought up typical TA concepts as we know it would have made a killing due to the fact the vast majority of traders being ignorant of TA concepts, they were just dumber or ignorant on how to trade technically, prolly the vast majority carried a rabbit's foot in their pocket.
As time progressed and word leaked out of TA it may have even worked better due to it being self fulfilling, that is until smarter traders began to capitilize on trading against it.
Then authors would have found it more profitable to sell the books than it was to trade.
Now every Tom Dick & Harry is aware of TA and when TA works and when it doesnt work is 50/50, per chance and coincidences. Conventional TA has no edge.
Thinking outside the square is required these days.