Robots incur more costs when you realise you can always just hire a waiter and not deal with robot maintenance and purchasing costs
It will all boil down to what kind of maintenance is required. A robot for $50k would pay for itself in saved wages in under a year, even less if it collected tips. A lot of smaller diners (Waffle/Huddle/Waddle/etc) typically have super low staffing requirements (line cook + 1 or 2 servers per shift, occasionally more) and could totally use robots due to the simple layout and standardization of the restaurants.
For people that don’t want to normalize state propaganda:
https://apnews.com/article/robot-cafe-waiters-kenya-technology-845cbb0bc610ef7f6fcbd86ef05803d2
As a tech enthusiast and software developer I think this is amazing! I would love to have them in my hometown in Spain :)
Korea will have to come up with solutions as the birth rate has been low for a long time