I'd use such a feature if I had to fill a table, and wanted to move to the same column on a different row. But with proportional fonts, the columns don't line up. So yes, it can move to the same x coordinate, but why is this useful?
It's useful for general text navigation, and writing code is an instance of that.
> I'd use such a feature if I had to fill a table, and wanted to move to the same column on a different row. But with proportional fonts, the columns don't line up. So yes, it can move to the same x coordinate, but why is this useful?
"Doesn't work well for use case X" != "not useful [in general]"
If your text is laid out assuming fixed-width fonts, and it's important for you to move to the same column in a different row, then just use fixed-width fonts and the method I described would work as you expect.
It can work with proportional fonts. Word for instance defines it well enough to be useful. Rather than down taking you to the same column on the next line, it just takes you to the character rendered at a similar x coordinate on the next line.