Doing a UI prototype for two pane file list that lets you browse files is EASY. Making a file manager is HARD.

Let's try to COPY A FILE from one place to another:

• Cross-platform
• Works on all filesystems, OS versions
• Network volumes
• Optimize for SSD/HDD
• Optimize for same-volume and cross-volume, cross-device copies
• Handle and report errors
• Detailed progress indicator
• Estimate remaining time
• Pause/resume
• Interactive options to overwrite/skip/ duplicates
• Symlinks
• Hard links
• Allow parallel copy operations but don't hammer the same drive (HDD)
• Correctly copy attributes, even when support varies between src/destination
• Sparse files
• Special files such as /dev/zero
• Channels
• Handle FS compression & encryption
• Sandboxing (macOS)

I don't even know if fman takes care of all that, but my point is that I can imagine one could easily spend 10% of that time making JUST THIS and I would consider it a great achievement if it actually worked.

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