It’s more about network outages than latency specifically... although in several remote locations latency is permanently low due to slow providers.
- Credit-card transactions don't have low-latency requirements, its 'nice' if they're quick, same as everything else. The bottleneck here is entirely dependent on your ISP tho. No 'edge-computing' here.
- Mobile orders. This will necessarily go thru to a central server. This is traditional client-server stuff. Again, no 'edge-compute'.
- Order receiving. Simple local data entry. Again, no 'edge-compute'.
- IoT devices. Hopefully these have local control systems without the server being in the loop. Control systems are not 'edge-compute' either.
'Edge-compute' is generation of knowledge at the edge rather than shipping raw data to a central server. This reduces required bandwidth.
What in your system takes a high rate of data and generates a low-rate of data for transfer to a server for further use. I see no analysis of raw data into a more processed form, this is simply traditional data entry and CRUD activites.
Requirement for low-latency implies a use of data that is time-sensitive.
What time-sensitive data is there in a single chicken restaurant??