I do that too for especially for phones/tablets to make sure that it isn't locked or anything like that. Too many stories of people returning the wrong thing on purpose or stolen devices and the buyer being SoL

I'd guess it's cheaper (combo of time and money) to do a robotic arm instead of trying to retrofit a whole fast food kitchen to adapt to robots instead of humans.

I'm personally more a fan of the robot cat waiter. It can carry three full serving trays full of food and tells you which tray your food is on. It still needs to have a human supervise the guests to make sure they take the right food, but... let's them get big table orders without risk of dropping them.