If the Primos or K&H people came up with a call. a basic whistle or tube or whatever that when you called it the largest most dominant bucks within hearing range would come 100% of the time without regards wind direction would you buy it?
A 100% no BS promise that if you blow this call you are going to have the biggest buck thats within hearing range at you stand.

My guess is that if it really worked after one hunting season big bucks would become extinct. After the next season, the same would happen to the remaining male population.

In the real world, who buys snake oil? I wouldn't.

A guy dies, and when he wakes up he is sitting in a boat with another guy. Each has a fishing rod. First guy casts, hooks an 8 lb bass, and reels it in. Second cast, same result. He says to the other guy "boy, I must be in heaven". The other guy says "no, you are in hell".

Put one hog in a pen and he will eat just enough. Put in two and they will both eat all they can to make sure the other one does not get it.

So I guess I would buy one.