I wrote a VB macro that displays the formula for a cell, next to the cell. Granted you have to add a cell (typically a column) to make space for it. It returns either a formula, or "constant" if the cell doesn't contain a formula. I could make it more sophisticated, but just those two things are enough to make spreadsheets a lot easier for me to follow.

Following spreadsheets is like trying to find something in my garage if all of the boxes have lids. But if the boxes are all open, I can find stuff in a jiffy, even if the boxes are disorganized.

Excel sheets are built visually so there is absolutely no sane way to parse them. Just the same thing as trying to restructure a pdf at the end of the day.