>>10464215mass market toys are sold in the millions.
If big toyline proves to be unpopular, there's going to be millions of pieces of shit that never sold.
For movies? You're going to get 5-10x what normal mass market toys are shipped at, so there's at least 5 million pieces of shit nobody wants that will be sold in dozens of stores and when the movie/cartoon/game/whatever flops, discount stores like Ross will start carrying it too.
The vast majority of products aren't made to order and stores take risks assuming The Last Action Hero is going to be the next Overwatch or Avatar, so they'll stock enough to meet that estimated demand. The United States is huge and to fulfill that market requires millions and millions of toys.
You're acting like companies have time machines or can hire psychics are real, and are in use by corporations to know exactly how popular something will be..