"...Literally, every old timer-regular poster has said dozens of times.. it won't work. "
One of the reasons I shy away from terms like "every", "all", "always" and "never" is that inevitably someone comes along and points out that whatever is being claimed is not true. So, here we are. No, this old-timer (I am on the shady side of 25 years in the Access development trade), doesn't say it won't work. As a matter of fact, one of the Access/SQL Azure databases I use nearly every day is, well, an Access/SQL Azure database that began life as an Access/Access relational database application which migrated to SQL Azure soon thereafter.
That said, beware of going too far in the other direction,"So that server setup in the cloud, would work.
nothing is needed other that what can be done in SSMS." The architecture for an Access/SQL Azure relational database application needs to be very solid and designed specifically with that in mind. It may not take much, depending on where the starting line is, but it's not going to be nothing.
Perhaps you should look into PowerApps as the mobile extension for your field people. It's a good option and low-code to boot.
Here are some videos on my adventures adding PowerApps to a desktop relational database application, although I started out with SharePoint lists. In future, I'll either go to SQL Azure or Dataverse.