I was referring to your comments about people trying to cut ahead of the line by ordering in person. If ordering in person was a regular option there wouldn't be any time advantage in ordering in person.
As for limiting capacity in restaurants, Disney has been limiting capacity in stores on property since they re-opened, with cast members at each entrance. There's no reason they couldn't do something similar at restaurants, & come up some kind of balance between walk ups an mobile orders. Kind of like fast pass (mobile orders) and a stand by line (walk ups).