Why is tab unaffected by font whereas space is affected?

[Eli Zaretskii]

> Cc: unicode at unicode.org
> Date: Wed, 22 Apr 2020 19:30:05 -0700
> From: "Asmus Freytag \(c\) via Unicode" <unicode at unicode.org>
> 
> Such global properties work well for uni-font displays like programming editors, notepad etc. where there's a
> corresponding single, global font setting. At that point, letting the font choice influence the "step-width" for the
> tab stop isn't too far fetched. But it would be a very specific use case and one that doesn't generalize well to
> editing rich text documents.

For the record: Emacs is not a uni-font editor.  You can have many
different fonts (and more generally, different typefaces) in the same
document.