It seems like just adding the ability to spread a calculation out over multiple lines and add some indentation would make the bugs everyone complains about go down by... a lot.
A3: IF(<boolean>, <result if true>, <result if false>)
A3: IF(B3, C3, D3)
B3: <boolean>
C3: <X>
D3: <Y>
In fact, people who are aware of Alt-enter produce buggier code: they end up writing longer formulas, with fewer intermediate results displayed, and have less visibility of the functioning of their spreadsheets.
Write simpler formulas.
Excel's formula language seems deliberately designed to prevent that.
Sometimes I'll get these spreadsheets with byzantine formulas that I have to copy it to a text editor and format myself to make sense of all the parenthesis.
The only disadvantage is if someone else isn't expecting the formulas to be like this, then gets confused when they can only see the first line.
Having the compose box fit itself to the formula size or give other indication that there is more to see is still a head-scratcher why they didn't do it.
???
:-(