It is correct that the "end" spoken of in Revelation was the return of Jesus Christ. But, the time of His of return is a point many people have difficulty seeing. That end time is a matter of the proper perspective.
It helps to remember the context of the scriptures so that we do not get off track, which a great many denominations / taught perspectives have done. In Daniel chap. 9 - 12, Gabriel is telling him of some things concerning the "end" of the desolation of Jerusalem. We know this from 9:24 -
"Seventy weeks are determined upon THY PEOPLE and THY HOLY CITY..."
The prophesy was only about Daniel's people -thy people - the tribes/children of Israel; and Daniel's holy city - Jerusalem. Gabriel was answering Daniel's question... when would be the end of the desolation of Jerusalem. But, Daniel didn't understand what he was asking, and thought he was only asking about their return to the already and previously destroyed city.
Therefore, the "end" spoken of in Daniel chap. 9 -12 was the end of Jerusalem and its complete destruction.
The next clue is the time of Jesus' manifestation on earth.... in the fullness of time (Gal. 4:4). 1 Pet. 1:20 tells us when Christ was manifested on earth that it was already the last days.
"Who verily was foreordained before the foundation of the world, but was manifest in these last times for you" (KJV)
Christ was born of the virgin Mary in the last times / last days. That was almost 2,000 years ago.
"God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets,
2 Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds;" (KJV)
As compared to previous ages when God spoke to the people through the patriarchs or the prophets - agents / messengers / angels - but in the first century A.D. God sent his Son to speak directly to the people. Vs. 2 tells us that Christ spoke to them in "these last days".
A=B=C. If one thing is equal to a second thing, and the second is equal to a third, then the first is also equal to the third.
The Bible plainly tells us that Christ was manifested on earth in "these last days" and that He spoke to the people in "these last days". Not our days... not the days when we are reading the scriptures, but the days in which He walked on this earth and spoke to those of the first century A.D. Those days were the last days!
So, then what were they the last days of? And, we now remember Daniel's question and the prophesy given to Daniel... the end of the desolation of Jerusalem.
Christ was sent to the lost sheep of the house of Israel (Matt. 15:24). Christ sent His disciples only to the lost sheep of the house of Israel (Matt. 10:6) John had told the scribes and Pharisees that the axe was already laid to the root of the tree when He was with them (Matt. 3:10).
Christ told them that the law and the prophets prophesied until John (Matt. 11:13). Christ told them that their days were the days of vengeance (Luke 21:22). Christ told them that all the shed blood of the righteous would fall on them (Matt. 23:35). Christ told His disciples that they would not finish going through the cities of Israel before He returned to them (Matt. 10:26). Christ told them that John would live to see His coming (John 21:22).
And, then we remember the question the disciples asked Him in Matt. c. 24. They had just shown Him the beautiful temple, and in vs. 2 He replies,
"...See ye not all these things? verily I say unto you, There shall not be left here one stone upon another, that shall not be thrown down." (KJV)
The disciples naturally begin to ask Him when that temple would be torn down. All of Matt. chap. 24 concerned the destruction of their temple.. the one standing in Jerusalem when they pointed it out to Him. To the Jews, that temple was the center of their lives. Its destruction / desolation represented the end of their world as they knew it. And, in vs. 34 He further stated,
" Verily I say unto you, This generation shall not pass, till all these things be fulfilled." (KJV)
Revelation revealed to those who received that prophesy that the "end" was about to come upon them, that all of the things in Revelation was shortly to come to pass (Rev. 1:1; Rev. 22:6, 7, 10, 12, 20).
Compared to Daniel when Gabriel told Daniel that the time was long and to seal up the prophesy (Dan. 12:4), the angel told John not to seal up the prophesy of Revelation because the time was at hand when the prophesy was given (Rev. 22:10).
The "end" that the Scriptures spoke of, the "latter days" of the tribes of Israel that are prophesied in Gen. 49:1-27, the "last days" that are spoken of throughout all of the NT books were the last days of that 2nd temple in Jerusalem, and the last days of the old Mosaic sacrificial covenant.
Contrary to what most "Christian" denominations are teaching, the Bible never speaks of the end of the physical cosmos / world.
Satan did trample the holy city under foot for 42 months; he did so through the agency of the prince of the people that came (Dan. 9:27) to destroy the city - the Roman armies under Titus in 70 A.D.
This may be startling to many, but if we can put aside the taught beliefs of a future "second" coming for just a little while, the words of God will shout out at you from the Scriptures.
His second appearance was promised to that generation (Heb. 9:28), as only that generation who saw His first appearance could have a second appearance of Him. Else every generation since the first century A.D. would have had to see Him in the flesh for the last 2,000 years.
He came in judgment and in glory in A.D. 70. He destroyed the temple, He finished the desolation of Jerusalem, He fulfilled the law, He brought His kingdom, and was anointed as our Most Holy High Priest forever. He made an end of the old covenant sacrificial system.
Christ has been sitting at the right hand of the Father ever since that judgment day, and He rules now. The process is in motion, and on-going. Judgment happens every single hour of every single day as we pass from this mortal life. Those that are in Christ get to go home to their eternal life in heaven to be with the saints that have already gone before (1 Thess. 4:16-17).
This perspective may raise questions for those who have not considered the actual meanings of the words in Scripture. A good deal of study is required to undo all of the misguided and false teaching of most denominations.
I have a few posts that you might like to investigate for further scriptural answers at ShreddingTheVeil. You might want to start with Part I of It's Not The End of The World, and work through Part X as these point out many of the scriptures that are too often glossed over. Then find Daniel And the End Times, The Whore of Babylon, The Beast of Revelation.
Further reading sources:
Daniel 11 - Prophesy Fulfilled here
The Symbolism in the Book of Revelation here
Preterism and Prophesy here
Questions and Answers here
There are many more sources that could be listed, but those are a few to begin. Christ fulfilled all things, and this is the perspective that is required (Luke 24:44; Acts 3:18). Fulfilled eschatology.
(All bold emphasis is mine.)