What is Space?

I see explanations of 3D space using 2D visualisations all the time. That rubber sheet analogy for Einstein's gravity/curved space theory is just one such (see attached video). I've also seen the expanding balloon metaphor. All this says to me is that we need these 2D representations because we can't acually conceive of the 3D reality. Perhaps that is a human "designed limitation": perhaps being able to see multi-dimentional realities would open the doors of perception to other worlds that we only suspect are there? Perhaps meditative insights or psychedelic drugs might prise open the doors of perception a little? Perhaps there a clues to this right under our noses but we are "encouraged" to ignore them by those invested in their own worldview?

https://youtu.be/wrwgIjBUYVc

Thanks for this, great video...Though it leaves me with more questions. He says we shouldn't explain Gravity in terms of Gravity which is what the image of the Earth creating a depression in space-time fabric does. I agree this is erroneous, but then in his explanation the apple moves through the curvature of the supposed 4th axis of time....

Isn't that sort of like explaining Time using Time?