And there's no discussion whatsoever about whether the negative impact on the mental model necessary for understanding Excel is worth the benefit for the unlocked cases.
I don't see why you can't just represent the cases with the existing structures and deal with that cost in cases that need it, because it keeps a simple mental model. Arrays are one of those things that mess with the simplicity here too - I'm sure there are plenty of hardcore Excel fans who find them trivial and/or essential but they're never intuitive and lead to all sorts of mistakes/delays if your spreadsheet is used by less expert types.
Keeping it simple seems a better direction in general.