> In Old English, the day was called Long Friday (langa frigedæg [ˈlɑŋɡɑ ˈfriːjedæj])—referring to the lengthy observances of fasting and religious services, making it a day of extended devotion—and equivalents of this term are still used in Scandinavian languages and Finnish.[16]
It's more about it being a long day for the faithful. Traditionally, you may have attended three hours agony, fasting, in addition to the liturgy (there's no transubstantiation), etc.
https://en.wikipedia.org/wiki/Good_Friday#Etymology