> A solution would be a monospace font with all glyphs the same width
The problem is, some code points are [defined to result in double-wide glyphs](https://en.wikipedia.org/wiki/Double-width_character#In_Unicode), even in monospace fonts. They have to be like that in order to be rendered correctly. The alternative would be to allocate fullwidth space even for halfwidth ("normal" for you and me) characters, which would also look bad.
In theory, SQLite shell _could_ have a look-up table to calculate box widths correctly, but it would take up too much space.