Excel needs the ability to work easily with an array of arrays of arrays.

Suppose, for example, that we define the names ag.Sales and ag.COGS, each of which references lists of specific account numbers or named arrays, and where the naming convention "ag." designates account groups. We need to be able to define the name ag.GrossProfit as ={ag.Sales; ag.COGS}...either by defining the array constant or by referencing two cells with those labels.

And ag.COGS needs to be able to be defined like {ag.Labor, A4012, A4013}, where A4012 and A4013 are specific General Ledger account numbers.

Also, of course, we need the ability to expand an array of arrays of arrays into an array of the lowest-level members. And we need to be able to combine (append) arrays within formulas.

We also need to use SORT and UNIQUE with that expanded list, and probably FILTER, as well.

This need extends beyond accounting applications, of course. But it's definitely needed there.