How the spirit operates on the individual allows them to see visions, or as in the case of the Bible writers have God's thoughts transmitted to them -
2 Peter 1:21
In any cases, they are under inspiration of the spirit, and the point is, it does not mean praying.
John was not just seeing things. John was experiencing them and writing them down as he experienced them. He was not dreaming nor simply inspired.
"Come up hither, and I will shew thee things which must be hereafter. And immediately I was in the spirit."
"Come and see. And I saw."
It is personal interpretation that concludes this was a series of dreams. Daniel had a series of dreams, and it was recorded that way. John never once claimed he was dreaming nor in a trance, nor simply inspired.
Revelation 1:10 could also be stated: "in spirit in the Day of the Lord". From the perspective of the Day of the Lord, the rest of the book was past, present (the Day of the Lord), and the future.
The book was not written from the perspective of the first century being the present.
In this verse we see 5 kingdoms had already fallen. In the first century, only 3 had fallen and Rome was the 4th kingdom.
Revelation 17:9-10
"And here is the mind which hath wisdom. The seven heads are seven mountains, on which the woman sitteth. And there are seven kings: five are fallen, and one is, and the other is not yet come; and when he cometh, he must continue a short space."
So at this particular present reference, the entire statue of Daniel 2 is in the past. The 6th Kingdom is about to end, and the 7th kingdom is the Millennial Kingdom, the Day of the Lord. But we also see the insertion of an 8th kingdom that interrupts the 7th kingdom for a short period of time.
"And the beast that was, and is not, even he is the eighth, and is of the seven, and goeth into perdition."
The 7th kingdom is not part of this beast at all. The 7th head is the temporary 8th kingdom.
Revelation 12 is the historical relationship between Satan and the statue of Daniel 2. Revelation 13 is the historical relationship of this statue with humanity. Revelation 17 is the historical relationship of this statue with religion. The ten kings never have a kingdom, but are ten humans arising during the Trumpets and Thunders who bring their nations and armies to side with Satan in some coalition that literally wipes out all religion on earth, and attempts to reconcile humanity with Satan against Jesus Christ without religion.
"And the ten horns which thou sawest are ten kings, which have received no kingdom as yet; but receive power as kings one hour with the beast. These have one mind, and shall give their power and strength unto the beast. These shall make war with the Lamb, and the Lamb shall overcome them: for he is Lord of lords, and King of kings: and they that are with him are called, and chosen, and faithful."
So it would seem that the stone started out during the 4th kingdom at the Cross, and grew to finally obliterate the 5 kingdom statue, around the time of the Reformation. It thus grew into a mountain filling the whole earth, the effect of the Gospel taken to the whole earth, and every nation. The 6th Kingdom was defunct as no single nation ruled the earth.
At the Second Coming, the 6th Seal, the 6th Kingdom is brought to life by Satan. That kingdom ends at the 7th Trumpet, when Jesus is declared King of the 7th kingdom.
In the midst of the week of days of the 7th Trumpet, God will either allow Satan 42 months as the 8th kingdom, or not.
So John left the first century, because what he was a witness to was not about the first century. Even the 19th century was in the past, according the present John was witnessing.