Visidata does far more than less-sheet. I see less-sheet closer to macOS's "Preview" than to visidata or excel: a tool to quickly look at the contents of CSV, not to work on it.

Visidata also gives us a quick preview even with large files (e.g 10GB, 2000 columns), but the entire file is loaded in the background, which might be a problem. Less-sheet on the other hand does not hold the data in memory beyond what's needed to fill the window, so the memory usage is similar independent of file size.

It's also a GUI instead of TUI, for people that prefer GUIs, and guesses the CSV parameters (separator, quote char, etc) while offering quick toggles to fix wrong guesses. Beyond that it only offers some column formatting options: hide, change data type and basic formatting.