Well, I agree with you in general, but Calibri actually seems to have some / cause some trouble. I recently filed a bug against LibreOffice regarding the rendering of ligatures in documents with Calibri, where you see things like:

https://bug-attachments.documentfoundation.org/attachment.cg...

... and it turns out that this is due to the use of hard-coded bitmaps for ligature hinting provided for some glyphs but not others, which confuses rendering engines.

https://bugs.documentfoundation.org/show_bug.cgi?id=155199