It seems to me, groff is another one of those programs — like lilypond from so long ago, or even like mencoder or some other conversion tools — that are sitting on the fence in terms of console programs.
groff doesn’t really display anything, that I can find. It converts between specific markups, changing, for example, text-formatted pages to man format. If all goes right, groff doesn’t show you a darned thing. But the output files are quite lovely.
Here’s an example. First, a raw man page converted to ASCII, then formatted to be readable.
Whenever possible, I try to avoid the Wall of Text effect. 
groff can do some other fun things too. Here’s a man page converted to a PDF document.
I know: Acrobat Reader. Ick. 😛
You can convert straight to PDF with groff and its included tools, without the need for ghostscript. groff translates between other formats too — including some I had never heard of. Here’s a memorandum macro letter, which was completely new to me until this morning.
Nice and clean output, even if it is in Acrobat Reader. Blech.
There is plenty of help online that will get you started with groff. My favorite discussion, as you will be able to tell as soon as you start into it, was here.
Like I said at the start, as a conversion tool, groff doesn’t seem to show much. In fact, in all those examples, groff never said a word unless there were errors.
So the question remains: Is a taciturn and laconic conversion tool still a console application? Should I have omitted this and all those others? Have I been wasting my time all these years? 😮 
Inconsolation 