I consider preterism incorrect because AD 70 was “A” Day of the Lord, Lk 17:22.
Specifically, it was the judgment of the City of Jerusalem.
Scripturally the “Day of the Lord” is defined as a period that allows a person or group of people to become aware of God’s opinion of certain behavior.
It reflects His opinion of the behavior making the recipient of the judgment aware of His opinion of that behavior.
This can be the judgment of a group of similarly disobedient people, as seen in Jerusalem’s destruction. It can also reveal God’s judgment upon an individual’s behavior.
As God’s judgment pertains to Christian behavior, it is meant for correction, as seen in 1 Cor 11:32.
Lu 17:22 And he said unto the disciples, The days will come when ye shall desire to see one of the days of the Son of man, and ye shall not see it.
Christians want to “See” Jesus but Jesus had just said in Lk 17:20-21 that they should not follow after people who try to deceive them by saying Jesus is here or there.
This is because the kingdom does not come with visible observation, and yet most contemporary Christians are waiting for the physical Second Coming.
Lu 17:20 ¶ And when he was demanded of the Pharisees when the kingdom of God should come, he answered them and said, The kingdom of God cometh not with observation:
21 Neither shall they say, Lo here! or, lo there! for, behold, the kingdom of God is within you.
Jesus told the Disciples that His future visible visitations would take the form of Destructive Lightening, Lk 17:24.
Lu 17:24 For as the lightning, that lighteneth out of the one part under heaven, shineth unto the other part under heaven; so shall also the Son of man be in his day.
When God’s judgments are in the world the world learns the right behavior, Isaiah 26:9.
Isa 26:9 With my soul have I desired thee in the night; yea, with my spirit within me will I seek thee early: for when thy judgments are in the earth, the inhabitants of the world will learn righteousness.
Isaiah 26:9 suggests that God’s judgment is not a final occurrence, because the “world” learns from the judgment and correction of the behavior results.
Jesus’ future visitations called the “Days of the Lord” are a time of destruction, (Is 13:6, 19:1) which is the scriptural definition of the “Day of the Lord”.
God disciplines everyone that He accepts as a Son, Heb 12:6.
Heb 12:6 For whom the Lord loveth he chasteneth, and scourgeth every son whom he receiveth.
7 If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not?
8 But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons.
It was not a time of salvation (Heb 9:28).
Thus it does not fit the scriptural definition of the Second Coming found in Heb 9:28, which describes the Second Coming as a time of “salvation”.
The Second coming occurs when a person “Repents” of unbelief and the Father sends Jesus to them.
Jesus said “It is finished” from the cross, and scripture contains only one instance of His coming after the crucifixion.
The Second Coming occurs in an individual’s life when they repent of unbelief and “all things” are restored at that point of repentance.
John the Baptist’s ministry preached repentance –
Mt 17:11 And Jesus answered and said unto them, Elias truly shall first come, and restore all things.
Ac 3:21 Whom the heaven must receive until the times of restitution of all things, which God hath spoken by the mouth of all his holy prophets since the world began.
An individual’s repentance from unbelief “restores” all things, particularly God’s relationship with Man.