Google-chrome – Chrome fonts weird rendering

my browser should automatically detect that the glyphs are not in the font and find an appropriate match

Unfortunately, this assumption on OP is only true for Firefox. Firefox uses fontconfig which does per-glyph font substitution; appropriate font is used if it contains concerned character.

On comparison between IE and Chrome, IE is slightly better in that it provides more extensive fallback on per-script basis and provide UI settings for fonts, though that didn't cover Egyptian Hieroglyphs. The font fallback mechanism for Uniscribe / DirectWrite, the components mainly for complex text layout, is described in this MSDN article.

Though Chrome finally supports per-script font fallback on 2012, users have to install extra extension to tweak them — one such extension is Advanced Font Settings. However telling all site visitors using Chrome to install extension isn't quite feasible.

About the original problem, one might want to investigate on the direction of font fallback mechanism, probably some other bad behaving font overrides Noto font, claiming to support those glyphs while in fact it doesn't. A tedious method is to remove extra fonts on system and re-add them one by one until the culprit is found.

Ok, so as I was writing the question I think I stumbled on the fix. In my installed fonts (Start/Run/Fonts), I somehow had Helvetica Black, but not any other version of Helvetica. It seems Chrome was picking the black version making everything look super bold. I certainly didn't manually install Helvetica Black on two computers in the last week, but it's possible that Chrome recently changed how it picks fonts or I used/installed some other software that installed Helvetica Black?

To recap, my fix was:

• Go to your fonts folder (Start/Run/Fonts)
• Find and delete Helvetica Black