I believe you missed the point.
If John wrote 666 and knew the person who fulfilled it, and it was in his own era, then why did he not just say, "It was so and so."
Then we wouldn't have all these Christians of his era and that immediately afterwards going around wondering who the Anti-Christ WOULD BE WHEN he got around to showing up some day in the future.
Ummm, because that's what Jesus wanted him to write? I'm sure we can all think of a lot of "better" things to say in the Bible than what's there. Funny thing is, we're not God.
Besides, it's not clear that the prophets always understood what God was telling them in their dreams and visions. It's quite possible that John did not recognize Nero as the beast until quite late in life, if ever. And we have no record that he ever told anyone about anything in the vision.
But we're back to speculating about things we don't know.
If John wrote 666 and knew the person who fulfilled it, and it was in his own era, then why did he not just say, "It was so and so."
Then we wouldn't have all these Christians of his era and that immediately afterwards going around wondering who the Anti-Christ WOULD BE WHEN he got around to showing up some day in the future."
Because he was writing stuff that he knew would get copied and read widely. Anyone having that stuff in his possession that says, "Nero is the Beast of Revelation" would potentially get in a lot of trouble. And you wouldn't want any trouble from Nero.
Nero liked to do things like dip Christians in oil, impale them on stakes and then set them on fire to be human torches to light up his orgies and wild parties. He eventually went completely insane because the Christians weren't screaming out in pain and that upset him greatly. The man was sick and twisted beyond imagination, hence his nickname "The Beast".
Aside from relying on the interpretation of 666, it's not too hard to trace the prophecies from the OT to figure this out, either. The timeline of Daniel's 70 weeks starts with the commandment to rebuild Jerusalem. It lays out exactly what happens all the way through the "weeks" of Jesus' sacrifice and the subsequent tribulation and destruction of the Temple. The blood ran in the streets during the Tribulation just as prophesied, the End of the Age (not the End of the World) took place, etc., etc. There is no precedent in OT or NT Scripture for the "prophecy clock" to stop as Lindsey and LaHaye teach. If you ignore their idea of clock stopping and look at the timeline as a continuous entity then it becomes clear what was prophesied and what took place exactly as prophesied.