The top only have ~11 devices and ~11 folders. How often do you really add a new device or a new folder? Is it really necessary that each device shares all folders which all other devices? If you go down this (more resource intensive) road you can take care of if by simply selecting all devices during first sharing (e.g. a share for all employees).
Also if you take e.g. a company with 100 notebooks on mobile connections, what good does it do if they are constantly burning through expensive data plans instead of just syncing with a master Syncthing node (which is backed up and 99% online anyways)?
And you also need to consider that Syncthing, although it is an excellent piece of software, only can be used in (work) environments where each node has similar rights to view/change the data, e.g. in a company you would not share accounting data this way. So while there may be exciting use cases like gathering weather data, etc. I think most of these setups are not a mesh system.