That’s the decision by the restaurant owner, whether to attract and retain better quality employees versus spending less money and having higher turnover of workers and workers that do not care about their work.
In most cases those restaurants also have better quality food (In and Out Burger versus MacDonalds).
I’m just pointing out that fast food restaurants that have a commitment seem to have long lines of customers. And it is not axiomatic that a rise in the minimum wage will lead to automation that eliminates employees.