You can have UTF-8 with groff using the preconv [1] tool, just pass the "-k" or "-Kutf8" paramater. It will preprocess your source and replace Unicode symbols with its groff special character form. Of course, the built-in standard fonts do not support many glyphs but it is no big thing to use a more Unicode friendly font like DejaVu Sans or Noto, check [2].

So this is my setup using MOM macros for nice typesetting.

But I fully agree on your last point, in the end I seldom need the Unicode universe for most of my documents.

[1] https://www.man7.org/linux/man-pages/man1/preconv.1.html [2] http://www.schaffter.ca/mom/momdoc/appendices.html#fonts