One question is whether you want to use grades for validating knowledge or for ranking.

You can say that A or B means pass (much easier for professors), or that 8/20 means pass and you have the whole spectrum from 0 to 20 to rank candidates if needed.

Nowadays, with international recruiting, I think grades becomes insignificant (graduates come from too many institutions, and grades aren't comparable) and companies need their own ranking metrics (hence the infamous leetcode questions).