alt Hacker News> (NTFS have performance problems and Microsoft knows, and even provided a kind of solution as far as I know with the developer FS or what they call it)
NTFS does not have performance problems. The difference between DevDrive, which uses ReFS (arguably a more 'resilient' file system than NTFS due to journaling) and a standard NTFS volume is the file system filters are either removed or in the case of Defender, put in async mode.
The file system filter architecture is the performance problem, not the file systems. It's a trade off to have a more extensible I/O stack.
I recall there was also an issue with how paths are treated in NT. I don't fully recall, but I think NT paths are parsed by the kernel early on, and the whole kernel operates on "cooked" paths. there was some major performance implications this had for WSL1 in addition to the filter driver architecture.
I also don't remember why they couldn't just bypass the filter stack for paths in a certain volume - WSL2-like I/O on WSL1 - but there must have been a reason.