What exactly is left? Does Elsevier have any employees?
Elsevier certainly has employees. According to their website, the company has 8.700 employees, most of them in Europe and the US (which is genuinely more than I anticipated before googling). Clearly not all of these 8.700 will be directly involved in handling papers.
I guess your deeper question is - what do journal editors (not the academic editors) actually do? My understanding from having lunch with such a person at a conference once is that it's a fairly heterogenous job - ensuring that decisions of the Editor-in-Chief(s) are in line with Elsevier policy (or finding a new editorial board in the rare cases that the existing one disappears), setting up and managing the submission system, networking with researchers like me at conferences, networking with library staff to ensure that these sweet, sweet subscriptions remain in place, collecting data to report to various indices, and naturally keeping one's eye open for potential new journals. And of course handling many emails (technical issues, complaints, etc.).
Generally, a single person will be handling a range of journals in the same broad technical area, since networking for Applied IT journal A will go hand in with networking for Applied IT journal B and C. Often (but not always), editors seem to hold a PhD in a field related to the journals they are handling.