I never did that myself so I wonder: what tools are typically used to pixelate text? And do those tools have to do the actual "pixelation"? Why can't you just h

I never did that myself so I wonder: what tools are typically used to pixelate text? And do those tools have to do the actual "pixelation"? Why can't you just have a tool in, say, Microsoft Word, that would allow you to select the text, and then chose "pixelate" option, and generate completely random pattern of squares in different shades of grey?