1. tv gives a quick summary of the count of rows and columns
2. tv shows all columns at the bottom that don't fit in the terminal. With vd I have to scroll on wide data.
3. tv guides the eye to missing data better with NA highlights
4. tv has sigfig logic that is better. I work with files where the decimal dust can become long. Those unnecessary characters pushes remaining columns off the screen. This means the user would need scroll over to see additional columns. I generally think it is better to avoid additional key presses if possible.
5. tv is fast for large files. It does not have to read and format all of the data like vd. tv is focused more on looking at the file and not operating on file. It does not have to do as much as vd. That helps tv with what it is uniquely good at. "Do one thing and do it well"
It does not matter if your file is really wide (lots of columns) or really long -- tv will give the user a compact useful pretty print of the data. Why not use vd as a TUI spreadsheet and tv for glancing at csv files. They are both great tools in my eyes with different purposes.