Considering the reality that people so often use Excel sheet to store small amount of data, it makes sense to access data in Excel sheet without running Excel app in parallel with AutoCAD app. This was I always did in the past, until MS stopped ship Jet Engine with Windows OS (when MS Access 2007 came out, which stopped using Jet Engine, and changed to use MS Access DB Engine).
The biggest issue with using MS Access DB Engine, is that it has to be installed (with admin privilege), and also has to be 32 or 64=bit explicitly. Even the computer has MC Access itself installed, it is likely 32-bit version. If AutoCAD is 64-bit, 64-bit Access DB engine has to be installed. If the user happened to stuck with older MS Office/Access (2007/2010), it may not be possible to have 32-bit MS Access and 64-bit Access DB Engine in the same computer. Since it is now year 2018, this probably not a big deal any more, but extra installation with admin privilege alone makes things a bit troublesome.
I'd consider using OpenXml to access data stored in *.xls/*.xlsx would be much better approach, if there is no need to actually open the sheet file in Excel app in the workflow. This way, you only have one extra DLL go with your Add-in DLLs. There are also a lot third party tool or toolkit based on OpenXml, many of them are free and very easy to use (but I always use OpenXml directly, it is easy enough).