Given that good management can have such a dramatic effect on the efficiency of this style of burger joint, this may well be a good investment for the company. I remember once going into a McDonald's, and seeing an absolutely
de-optimized crew. Basically, they seemed to be trying to all use the same station at the same time, trying to maximize the length of the queue formed and minimize throughput. It literally took me 10 minutes to get a burger.
Of course, this also applies to the workers under the manager as well. My wife drives me crazy in this way. There are some people who will interact in a group by modeling the future pathways, tasks, and schedule of everyone around them, then navigate those models to avoid conflict in time and space. Then there are some people who can't. As far as I can tell, my wife doesn't have a fine-grained enough internal sense of time to be able to do that. I almost stopped dating her early on, because she once kept me waiting 45 minutes in front of the locked door of her apartment, because she was having a conversation with her CEO. I also recall a recent instance cooking with her in the kitchen, and was rinsing 3 pieces of raw meat (1) -- she interrupted me between piece 2 and piece 3 and left me hanging there with contaminated hands while she washed/processed an entire leek. I also remember a band-mate of mine who couldn't "add time" in her head when travelling to gigs, so would always be late. (I know this is the specific case from conversations while planning to drive somewhere.)
It was a very good lesson on how job satisfaction doesn't need fancy cafés, ball pits and slides.
I think one of the best possible rewards is "good working." When people really mesh, there can even be a high.
(1 - Which you're not supposed to do in the US, but I do because my wife grew up in China, so she has a much greater distrust of commercial food processing.)