You're saying that text are 1D, while we're saying that it's not. If it were, we would write text on a long rolling tape. If it were, we would write matrices like this:

  [1 2 3; 4 5 6; 7 8 9]

Instead of

  |1 2 3|
  |4 5 6|
  |7 8 9|

The concept of vertical space to separate blocks of text is important. The concept of physically moving the next chapter to a separate sheets of paper in books is equally important.

In code we split the code into files. Then within the files we arrange the code with lines and indentation. That's all for humans. The computer eagerly throws those away.

ADDENDUM

> meaning that algorithm concepts are best represented in text? Again, I doubt that very much.

One of the (most?) important things that algorithms encode is time. Because an algorithm is a description of a process. The only good representation would have been to snapshot the evolution of state.

But that's wasteful. So instead we have statements and expressions that we assume are atomic. Then we have identifiers for referencing and finally we have procedures and functions to cluster those statements and the associated call/return pattern or the single jump/goto to economize on writing.

So code is at least 2D as operations are described in a line and the lines are arranged by time. But the lines are not linear, instead they are grouped into labelled units and the proper evolution are functions call and jump instructions.