Texture created for bitmap font glyph, with a fixed size in the font, this size could be much bigger than the needed size in application.
Then a scale factor is applied to these textures when drawn.
Now, instead, we will create smaller bitmaps and create texture from them with reduced texture size (that is not needed).
Newly created bitmaps could be :
1/4, 1/16, .. of the original image with no detail loss for user