70 AD was only a physical fulfillment of Jesus' prophecy that the temple would be destroyed. That prophecy required a literal fulfillment. It was also a spiritual fulfillment and sign of Jesus' redemptive power because it halted the sacrifices and made any component of Mosaic Law literally impossible to follow or obey.
Prophecy always requires a literal, testable, provebale fulfillment. It is never fulfilled only in a spiritual way. That would violate prophecy we know has already been fulfilled, and fulfilled in literal ways that agree 100% with a given text. When it is stated that when Jesus comes back, He will return in the same way He left, and every eye will see Him, it means exactly that. So we know Jesus didn't come back in 70 AD.
Matthew 24:20-34 20 Pray that your flight will not take place in winter or on the Sabbath. 21 For then there will be great distress, unequaled from the beginning of the world until now--and never to be equaled again. 22 If those days had not been cut short, no one would survive, but for the sake of the elect those days will be shortened. 23 At that time if anyone says to you, 'Look, here is the Christ!' or, 'There he is!' do not believe it. 24 For false Christs and false prophets will appear and perform great signs and miracles to deceive even the elect--if that were possible. 25 See, I have told you ahead of time. 26 "So if anyone tells you, 'There he is, out in the desert,' do not go out; or, 'Here he is, in the inner rooms,' do not believe it. 27 For as lightning that comes from the east is visible even in the west, so will be the coming of the Son of Man. 28 Wherever there is a carcass, there the vultures will gather. 29 "Immediately after the distress of those days " 'the sun will be darkened, and the moon will not give its light; the stars will fall from the sky, and the heavenly bodies will be shaken.' 30 "At that time the sign of the Son of Man will appear in the sky, and all the nations of the earth will mourn. They will see the Son of Man coming on the clouds of the sky, with power and great glory. 31 And he will send his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of the heavens to the other. 32 "Now learn this lesson from the fig tree: As soon as its twigs get tender and its leaves come out, you know that summer is near. 33 Even so, when you see all these things, you know that it is near, right at the door. 34 I tell you the truth, this generation will certainly not pass away until all these things have happened.
Amillennialists try to force the word "this" in verse 34 as applying to the Disciples, therefore, Jesus had to return before the Disciples died. Jesus is not speaking of that generation in verse 34. It is clear from the wording that He is speaking of the events He has just laid out beginning in verse 15. The generation that sees those things can anticipate Jesus' return at that time. You don't have a time of distress in 70 AD that has been unequalled since, so there is no way that the generation of the Disciples can be the generation Jesus is speaking to. That is just basic hermeneutics. Jesus is speaking of a future generation that will experience the events He lays out. Jesus never directly answered the Disciples when they asked Him when He was going to return and establish His Kingdom. because His return was going to be in the range of the future that they would not understand.