Book of Enoch story of pre Noah reason for the flood

Nephilim, the 200 watchers came down and mated with the human daughters of eve, cannibalized people, drank their blood, conducted jeffrey epstein things and genetically manipulated people with animals, got sent angels to cut the big world trees so that the giants, the kids of the watchers wouldn't be able to climb them and survive the flood.
Enoch is the father of Methuselah, who was the grandfather of Noah