We have seen what works, we also know that horses don't go lame by living on concrete, that dirt floors aren't always best, and so many other things.
My last word on the subject, the tradition that we come from in the UK has many hundreds of years of history of using the horse as a work and pleasure animal, whereas the Americas has a much shorter history. Not everything that was learned over those many centuries still holds true, but as with everything else, science keeps proving that a lot of the old knowledge was actually correct, progress does not always bring benefits.
So yes, I will stand by the benefits that I have seen, I will add to it that if I strapped and wisped my horses daily I would not only be fit, but I would be at my correct weight.
Now you post away, have at it, I find your internet search skills are certainly great, your use of bold is exemplary, your actual hands on practice and understanding of horse husbandry, mmm not so hot, but that's OK, experience will bring that.