As you say yourself, you're a hairdresser not a scientist.
I appreciate that from a hairdresser perspective the hair might feel nice to touch and style, but the product you're flogging still doesn't actually repair broken bonds. None of the 'knock off' products do that.
I can buy any number of smoothing treatments but there's only one product that repairs the internal damage and that's the one I want to use and recommend.
It's like comparing an Aeroplane to a bicycle. They're both methods of transport but you'll struggle to bike across the Atlantic Ocean.