Why the 70 Generations in Enoch and Luke Have Nothing to Do with Jesus Destroying Demonic Powers in AD 70

There are some Preterists who think that 1 Enoch contains a prophecy that confirms Christ's coming judgment in AD 70. The text reads as follows:

 And when their sons have slain one another, and they have seen the destruction of their beloved ones, bind them fast for seventy generations in the valleys of the earth, till the day of their judgement and of their consummation, till the judgement that is for ever and ever is consummated. In those days they shall be led off to the abyss of fire: 〈and〉 to the torment and the prison in which they shall be confined for ever. And whosoever shall be condemned and destroyed will from thenceforth be bound together with them to the end of all generations.

 It's argued that Luke is using Enoch's chronology, as he has a genealogy that adds up to 77 generations from Adam to Jesus, which supposedly matches Enoch's timeline (70 generations from Enoch who is 7 generations from Adam). Now, even if the numbers were right, and they are not, Luke would merely be displaying that the demonic powers were judged within Jesus' generation (i.e., within His earthly lifetime or at least by the end of it), since Enoch states that they will be bound for 70 generations and then judgment. If this had to do with the temple, they would be bound for 71 generations, not 70. It must be remembered that a generation in Luke is specific to the person to which it refers as well. One cannot make up some number, like 40 or 70, and place it on each generation, as it doesn't work out that way. Some in Luke's genealogy lived for hundreds of years and others died young. One could say that it only refers to the time of a person before they give birth to the new person that then starts a new generation, but even that does not work out, as Abraham begets Isaac when he's 100 years old, and Jared begat Enoch when he was 162,  but Enoch begets Methusaleh when he's 65 (same for Mahalalel with Jared). The generation, then, refers to the lifetime of the person, not beyond it. So even if the numbers worked out, it still says nothing toward Jesus overcoming the powers in AD 70. Instead, it would relate His judgment of the powers at His early ministry and/or the cross and resurrection. One could not argue that Jesus was of the same generation as that of AD 70, as the time He makes His "this generation shall not pass away" statement, a new generation has already come. Also, Luke's generations clearly end when one dies. Hence, Jesus' generation does not go past His death in Luke's genealogy, even if used differently elsewhere.

However, 70 in Enoch is likely a figurative number, as apocalyptic literature often uses septadic numbers to represent completion (in Enoch the completion of the temporary bondage of the fallen angels). It's likely then that the 70 isn't literally 70 generations, but rather meant to end in the author of Enoch's day. Either way, it doesn't work out to AD 70.

But what's even worse than this is that Jesus is not 70 generations from the time this occurs in Enoch. People assume that this is 70 generations from Enoch, but the time of their bondage is the flood. This statement is directed to Noah in the apocalyptic narrative, not Enoch (v.1, "Then said the Most High, the Holy and Great One spake, and sent Uriel to the son of Lamech, and said to him: 'Go to Noah and tell him in my name "Hide thyself!" and reveal to him the end that is approaching: that the whole earth will be destroyed, and a deluge is about to come upon the whole earth, and will destroy all that is on it). 70 generations from Noah comes out to 80 generations from Adam, not 77. Then you would need at least one more to make it to AD 70, so now we're at 81. Obviously, 77 doesn't match up to 80 to make it about Jesus, and the 70 generations of Enoch plus 7 generations to Enoch don't match up to 81, not to mention 78, which is what was needed even if the original numbers were right.