At least part of the reason is flexibility. For example Windows has the File System Filter Driver system [0] which allows you to execute arbitrary code to observe, modify or prevent any (filesystem) I/O action. That's for example how a virus scanner can scan any file before it's opened (and of course any Windows system nowadays has a virus scanner running, even if "only" Windows defender. But you can have any number of such modules running (for logging, encryption, backup, etc), each being called for every file access.

Another problem is that the Windows Api is designed differently from the Linux Api. Windows is optimized for network drives, Linux more for local drives. Software designed for Linux often hits access patterns that don't perform well in Windows.

0: https://docs.microsoft.com/en-us/windows-hardware/drivers/if...

sometimes i wonder why does explorer listing 100k files in a path can take minutes.

And searching the whole disk for a partial filename? tens of minutes.

I can do both in a database on the same machine in seconds...