So much of what Snyder filmed was cut from the theatrical cut.
I think they said something like 40% of the theatrical cut was shot be Wheldon, and completely changed the movie’s tone, focus, etc..
Synder’s vision had included ways to incorporate a GL Corp film, IIRC, an expanded story-arc for Cyborg, a better understanding of the dream sequence of Darkseid, and of course, from the trailer, Diana discovering ancient stories about Darkseid.
So if the theatrical release was 120 minutes – less 40% = 72 minutes of Synder.
Synder cut is reported as being 214 minutes. That is almost 2-1/3 hours of story we have never seen.