a combination of studio interference, budget overruns, going over schedule, test screening bollocks and director's hubris.

Coppola wanted to do both an accurate-in-spirit adaptation, pay homages to Murnau/Herzog, Universal and Hammer Draculas, do some of his own stuff and then some as it goes - all at once in no particular order. so the film is overstuffed and it shows. then there is studio with an expectation of a Dracula movie that is slightly more sophisticated than usual but essentially a vampire movie with vampire stuff, then Coppola delivers this Ken Russell-coded lavish mystic melodrama that moves at glacial pace and studio goes "whoa easy big feller" and because that's post One from the Heart Coppola he is not in the position to argue so gotta compromise - which led to choppy choppy because the storytelling is too cerebral, there is too much gore stuff, too much sex stuff, too much vibes stuff and so on - and there's a runtime cap on top of that.

As a result, there is like half an hour of deleted scenes on DVD that should've been in the movie and the workprint showcases how the ending was originally supposed to unroll - basically - it got very heavily streamlined to fit the runtime and communicate the basic point - so it falls apart narratively and stops making sense as a ritual it was meant to be.