I agree.
And for writing, the difference is even bigger than for reading. Thus, what we need is the reverse tool, that translates our beautiful formulas into the damned code!
- OCR a handwritten formula (unreliable but the most convenient)
- make the user write serialized code and show it as formula (basically this submission, but also latex etc. - misses the point)
- force the user to design the formula tree with some graphical editor and fill it with values and identifiers later (office suites do this and it's such a pain to constantly switch between keyboard and mouse)
Eg. by hand, you can write down the denominator of a fraction before the numerator. While latex require numerator before denominator.
The problem is that you have to jump which "by hand" is natural (start writing slightly lower) while with keyboard requires switching to mouse and back or remembering shortcuts and modeling the tree structure of your formula in your head to know where the shortcut will jump.
Same with introducing new levels of nesting.
That's why I prefer just writing code for formulas over graphical editors.
But even without all that, a very basic thing that you can do is move around the matching pairs of braces (and brackets, and other paired things) using %
If you do not want to move, but only see where the matching brace is, you can "set showmatch" and it will flash the matching brace when your cursor passes through the other one. This is really helpful for writing nested formulas (although a better strategy is to add a lot of newlines and whitespace so that the structure of your formulas is clear).