The a7r iii (and other a7 cameras) have received a lot of criticism regarding their menu systems. I suppose the criticism should be expected as more features are added to the a7 cameras and the menus become increasingly complex.
I really believe that the solution is for Sony to create a way for the end user to customize the camera menu for his/her own needs. If you agree, may I suggest that you chime in to encourage Sony to create something that allows menu customization, and spread the word to other photographers. Maybe as a community, we can get Sony's attention and inspire them to action.
Here is a detailed description of an idea to solve the menu problem.
https://community.sony.com/t5/Join-the-Inspiration/Sony-a7r-iii-camera-menu-idea/idi-p/655678