AutoCAD doesn't have a database, or keynotes - perhaps you're referring to the ACA vertical? Best to be specific.
Databases are more efficient for data management but there are some tradeoffs. File-based databases such as MS Access are sensitive to numbers of simultaneous users. Although SQL Server is better suited, it requires additional investment in management (as does Access, although not as much) and server-side architecture. Not everyone wants to go to that level of work.
Most products are also sensitive to release versions. Dredging up an old example, a *lot* of users used JET to connect to MS Access databases. However JET is only 32-bit, so when they switched to 64-bit programs they were left high-and-dry until the ACCDB Access driver was made available. Even then there were problems as many corporations were using 32-bit MS Office which didn't permit a side-by-side install of the 64-bit Access driver. So don't expect a no-pain solution - you're trading one set of problems for another.