Should we invest in finding a SINGLE version control tool that is suitable for all artifacts and use cases (many small text files AS WELL AS few but huge binary files, and anything in between)? Or rather should we invest in an abstraction system that spans multiple, but optimized for the specific content? Eagerly awaiting what suggestions you may have for us!

Not really sure what you mean by "abstraction system" - do you mean a front end for various tools?

The standard tool now would be git. And that would be great for source files. It depends what you mean by binaries. If you mean the outputs of builds then I would not avoid putting this in git (or any source control tool). But if you mean gif's etc then that would be OK but you have to start thinking about the size of the repositories and the distribution of your users. A large git repository can take a long time to clone depending on network.

For build outputs, libraries could go in a nexus like product. Deployable binaries could be in container management images, something like docker.