I definitely am in the camp where the book of revelation was written as prophecy for the Jews and Christians alive at that time alerting them to the upcoming persecution under rome.
Revelation opens up with a handful of letters to a handful of churches
666/616 is not the mark of the Devil or his son but is the numerical value of the hebrew language. It’s similar to how we can say 1 is A , 2 is B and C, BA, or Ab is 3.
Plus there are all kinds of other clues we can look at showcasing why 666 was a generational threat.
With that said, Tim Mackie has shown some
Evidence that perhaps revelation severe s the dual purpose of not only altering that generation to their anti christ, but also altering each generation to the evilness of powerful people who rule over powerful nations that echoes again and again.