here here :
By your logic, the seller of a music store may not know the Beatles because they are not from his era?? to
= = = is = is = is = is = is
And according to your logic, the salespeople of music stores should conservatories graduate plus a postgraduate degree in world music history? Are the book sellers philologists?
I'm not sure that the stores will attract such salaries to the sellers, and if they pull - then you, the buyers, will have to fight for it.

= = = is = is = is = is = is
I worked as a consultant in stores of two different sports brands and knew the composition, purpose and history of the creation of each model of shoes, always remembered the price and what sizes are in stock.
I am not saying that this is very useful information, but that the seller should know the whole range. This greatly contributes to the interest in what you are selling. I myself often go to bookstores and in 98% of cases I immediately, even without the use of a computer database, showed where the book I am looking for, regardless of the author's fame.