I guess you can not explain why it is okay to not wear the mask indoors for most of the time while in crowded restaurant.
It's not that complicated.
Wear a mask as much as possible especially when distancing isn't possible.
No one is arguing that masks can be used 100% of the time. It's about minimizing risk, not eliminating it completely.
Are crowded restaurants a thing? Every restaurant I still go to has reduced seating and/or plexiglass between tables. Plus vaccine check at the door.