Do you believe there's a somewhat fixed wage threshold (for now or 20 years later) that when it's passed McDonalds begins to consider replacing workers with self-service machines?

Or that the self-service machines are going to arrive regardless of the wage, with the only difference being McDonalds keeping workers on $10/h wage 3-5 years longer than they would keep the $15/h workers?

What happens when the entire self-serving machinery costs as much as it does to pay one or two employees for a year? Does it make sense for McDonalds to keep human employees at any wage?