It certainly helps for sure, but like Blinkers its a small factor and is grossly overstated.
It might give me a 1-5% edge on the day, if seeing what a horse looks like was that important Bevan Sweeney would be a super star punter, which he is not.
Its like anything Hesi, you can have the knowledge but not know how to apply it, as is the case with 95% of people connected with the industry.
Take fishing for example, why do 20% of those who fish recreationally catch 80% of all caught. Punters are the same the world over in that they repeat the same mistake every Saturday. Those who catch less fish do so because they take the wrong bait, wrong gear, wrong spot etc & want a miracle fish as well, they might get lucky occassionally like punters do, but most like punters go home empty handed.