The important and very crucial factor helpful in interpreting the Book of Revelation correctly is the date that it was written. there is confident agreement by a majority of scholars that put the date that John wrote this book around A. D. 95
There are several reasons for this. A letter written around A. D. 180 by Irenaeus, a disciple of Polycarp (who was a disciple and successor of John) states that "pronouncing the name of the Antichrist would be incurring a risk and if it were necessary at the time it was written, it would have been revealed by Christ." They did not know the name of Antichrist. If it was Nero in their past, then they would have stated it. Nero was an antichrist. All the people in history who have persecuted Christians or create lies about Christ are antichrists as well. But Nero was only small change in comparison to the Antichrist during the Great Tribulation period. Clement of Alexandria, Origen and Eusibius all support the date of Revelation given by Irenaeus which was around the end of the Domitian's reign.
Did you get who Irenaeus was? He was a disciple of Polycarp, who was a disciple of John, who wrote Revelation. Don't you think that he knew the date Revelation was written? Do you know your grandfather, what he did and when he did it, especially if he did something historical? This is equivalent to the grandson of Beethoven knowing when grandpa wrote his first symphony, in 1800.
Further info:
Smyrna was not mentioned anywhere else in scripture suggesting that it was a newer church which was started late in the first century.
Polycarp was said to be the Bishop of Smyrna and born around 70 A. D. Since he was a disciple and successor of John, then this church began decades after the destruction of Jerusalem.
Finally, Polycarp said that no church in Smyrna existed in A. D. 67.
Not convinced yet? There's more.
If John wrote Revelation before A.D. 70, it would overlap Paul's letter to Timothy who was in Ephesus at the time.
The problems Jesus points out in Revelation concerning Ephesus and Laodicea are not evident in Paul's letters.
John probably did not move to Ephesus until after Paul and Peter were martyred. Nero killed Christians and their prophets including Paul and Peter. That was his style. He would have also killed John if he was around.
But John became banished to Patmos. That was Domitian's style of punishment.
And all you can say is "nobody actually knows". Preterists don't want to know, they discard any evidence that works against their view. It is like what we see the Left-Wing Media and government doing today. Ouch, it you are a Left- Winger! Don't want to get political, really. But it is interesting when you find out about people with opposite views on religious topics, usually they are on the opposite sides in politics too. And don't mention anything negative about Trump, I will slam dunk you hard! Just kidding. No, if you are really a Democrat, I will probably end my dialogue with you, because there is this impenetrable wall there that separates us. It's beyond us really, it's supernatural in scope. We war not against flesh and blood but against powers and principalities of darkness. The world is now controlled by dark forces.
There are many who believe it was written before 70AD I have books with many Christian writers writing about it and have seen debates about it but nobody can prove when it was written and nobody outside of the bible have biblical authority.
I go by history and the purpose of revelation