[pjc50]

Much of the cost is imposed by semantics and the security model; there's no silver bullet solution that can be imposed without turning it into a different filesystem with different semantics and/or on disk representation.

At one point they planned to replace it with a database filesystem, but that was too complicated and abandoned. That was probably the end of replacement work on NTFS. https://en.wikipedia.org/wiki/WinFS

[nullindividual]

WinFS was never designed as a replacement as it rode on top of NTFS. It was a fancy SQL Server database that exposed files as .NET Objects for API interaction.

Sans the API piece, think of it like storing blobs in SQL Server, just like SharePoint does.

I was lucky enough to play around with beta 1. Not much you could do with it, though.