Deductions & credits

I'm not sure this answer explains the splitting of medical deductions (on a single page in TurboTax).

I figured it was because one party might not hit some minimum... but I'm not sure.

In the case of my wife and I (over 65), we had records to split the total on the state return. It turned out to be nearly 50:50. But what if it wasn't? How would that really matter?