So what happens when you have a 10 deep nested if tree?

Your answer would be to not do it because it doesn't fit nicely in a 2d page. My answer would be to put it in a 1d line and not bake semantics into presentation.

But you can't pretend that the space of programs isn't infinite dimensional when the space we work in is only 3d. Regardless of how clever you are using a medium with a dimensionality higher than 1 for semantics will always result in expressions you can't express.

This is why we've stuck with text.

It's 1d, but we can make it 2d to help understand what is going on visually in the simple cases humans can understand intuitively. Yet it is complex enough to represent any possible object.