If you approach the Ascension through the lens of the Catholic Church's catechism you have three offerings as to its meaning - the assimilation of Jesus' humanity into the kingdom of God and the prospect of His return, Jesus' entering heaven preceding us giving us hope of doing likewise; and, Jesus as permanently established mediator for humanity in heaven, ensuring access to the continual outpouring of the Holy Spirit.
It is the third that has always interested me because Jesus rather emphatically tells us that unless He goes, the Holy Spirit cannot come. I expect you can spill much theological ink pondering why this must be so but it occurs to me that, at least, one potential meaning is that now the focus shifts from Jesus as model to the work necessary to be done by each and everyone of us if we are to be reborn of the Spirit.
It is as if Giotto's saints (depicted above) are fixing in their minds an image of what it might be to become ultimately human but that image must go away if each us is going to have their own image uncovered, made as a likeness after the divine. The problem then it seems to me is that too often we do not turn away (and in) to find our own image of the living God, animated by the Spirit, but settle for clinging to the model; and, the model, in some important sense, is gone or rather 'here' but yet not here, necessarily occluded so we might have it made anew in ourselves.
This is akin perhaps to the Buddhist saying that if you meet the Buddha on the road, you should kill him, not for extolling violence but to avoid the subtle ways an image or icon becomes an idol - even one that is the actual presence of the perfect being.
Holiness can only be lived, each time anew, in and amongst persons, it can never be allowed to become static and Jesus' Ascension is a profound image of this (that dangerously can simply become the opposite - one more belief to get fixed and right).
And, ultimately, of course, Jesus' return is not a 'descending' but when each and everyone of us has 'ascended' to the place where our divine nature has been restored, rather than looking into the heavens, we then find that the heavens are all around us, in us, amongst us. The humanity that Jesus is, is us.