But that can be achieved by giving the retailer a one-off access code/secret which will be handed to the delivery driver by the retailer's company?
At no point does "preventing random people in your garage" required a greedy middleman in the path between you and whoever you want to give your garage door access code.
At no point does "preventing random people in your garage" required a greedy middleman in the path between you and whoever you want to give your garage door access code.