Comment by Tobani

Sure in an ideal world we don't need to worry about resources and everything is easy. There are very good reason why they are separated now. There have been systems like 4th dimension and K that combine them for decades. They're great for systems of a certain size. They do struggle once their workload is heavy enough, and seem to struggle to scale out. Being able to update my application without updating the storage engine reduces the risk. Having standardized backup solutions for my RDBMS means is a whole level of effort I don't have to worry about. Data storage can even be optimized without my application having to be updated.