In other spreadsheets (the old Quattro Pro and LO Calc), I have seen attempts at a "formula building" utility. Other than the function wizard (has it seen any updates in newer versions?), I have not seen any good attempts at a formula builder for Excel. I'm not certain why no one has tried to make a good formula builder for a spreadsheet. I'm guessing it is deceptively difficult to program something flexible enough to be useful for a wide range of formula styles but still be truly helpful.

FWIW, I find myself avoiding big, complex, single cell formulas. I prefer to spread something like that out over several cells. Then, if I decide to combine them, I can use the formula text in each cell as I build the larger formula in a single cell.