Earlier quoted context omitted.
Drawing text is the most expensive in a GUI.
That's only true for TrueType Fonts in graphical mode. In text-mode, characters are "drawn" by simply writing their ASCII code point into VRAM and writing another byte (two 4-bit values really) in an additional "attribute" buffer to set the foreground and background colour. Programmers can swap out the default character set to provide their own typeface and graphical characters for use as window borders, shadows, etc…
This in addition to the fact that, as others have pointed out, the old-style text mode really doesn't lend itself well to Unicode, to the new (sic!) terminal colour systems of the 1990s, nor to proper boldface+underline+italics. (The latter is one of the reasons that commercial DOS programs from 1-2-3 to Quattro Pro were switching display adapters into graphics mode and rendering their TUIs by drawing graphics, with BGI in the case of Borland, back in the late 1980s and turn of the 1990s.)
With post-VGA blitting capabilities one can of course do things like pre-load glyph bitmaps into off-screen video RAM and blit them into the display, potentially a lot faster than having the main processor write the glyphs directly; but it is still not as simple as writing 16-bit character+attribute pairs, to do what modern users generally regard as the basics of TUIs in these modern Unicode, 24-bit colour, full ECMA-48 attribute support times.