My point wasn't that it would be impossible to create a new kind of solution. It's enough that it would be a massive undertaking for unclear benefit, if any.

If we get rid of hierarchical filesystems, what replaces got, for instance? Perforce has some ability to project different filesystem hierarchies, but even if that were enough (it probably isn't), porting all those tools and projects to perforce would be an incredible amount of work without a clear upside for users of version control systems.