In two years we're going to see a lot fewer eat-in restaurants, a lot more kitchen-only joints, and those kids who used to be wait staff will be on the dole, or marching in the streets. Much like movie theatres, cheap quality dining is going away.
In contrast, your argument for why eat-in restaurants are about to disappear in large numbers is entirely based on a decrease in supply of cheap labor. You don't argue at all for why there would be a decline in demand. Perhaps customers changed their habits after the COVID lockdowns, but at least on the short term, I feel like I'm noticing the opposite effect: people really want to do stuff outside of their house.
I understand that some of the more struggling restaurants would be driven over the edge by higher wages, but it seems spurious to assume that this will cause a large shift in the market all by itself.
And it's even more spurious to just assume that this will drive large swathes of former wait staff into unemployment. Similar arguments are made carelessly in the minimum wage debate, where people mistakenly believe that there is consensus among economists that it drives up unemployment (https://en.wikipedia.org/wiki/Minimum_wage#Surveys_of_econom...).
Theatres might have made it, if hollywood wasn't also at an all-time low in customer esteem and (IMO) quality of output.