At the moment of “time” regarding +John 14:28, Jesus’ statement was according to his incarnation. He (Jesus) was of the flesh yet The One who sent him was pre-emminent. (Ref: Parable of the vineyard tenants).
Jesus, while being God Incarnate -so as to fulfill the desires of God- was not above The Father. He was “of the flesh”. Numerous times in the Gospels we see that Jesus suppressed His deity so that The Father would be glorified. God then glorified Jesus in His miracles and actions and finally on the Cross.
Jesus raised several from the dead yet, in doing these miracles, always glorified God. Many other instances can be used.
Your reasoning does not explain the following passage from 1 Cor 15:22-28:
22 For as in Adam all die, so in Christ all will be made alive. 23 But each in turn: Christ, the firstfruits; then, when he comes, those who belong to him. 24 Then the end will come, when he hands over the kingdom to God the Father after he has destroyed all dominion, authority and power. 25 For he must reign until he has put all his enemies under his feet. 26 The last enemy to be destroyed is death. 27 For he “has put everything under his feet.”[c] Now when it says that “everything” has been put under him, it is clear that this does not include God himself, who put everything under Christ. 28 When he has done this, then the Son himself will be made subject to him who put everything under him, so that God may be all in all.
It seems to me that Jesus is still teaching that the Father is greater.