These are already the lowest paid jobs, it's not like you'll be able to lower wages. I question how AI will increase the productivity of the jobs that are largely dependent on manual labour. It's not going to make the food cook faster, it's not going to make the server run and cover more tables, it's not going to make the construction worker put in nails or lay the flooring faster.

So the only benefits would the to be able to hire less skilled workers, but there is more to work than just knowing how to do a job. You need hand-eye coordination, you need physical strength etc. So there are other factors limiting the labour pool and pushing up the wages, not just mental factors.