You skip the physical line. The whole point of DAS. Many who have utilized it including close friends of mine would most often wait in shops or get a coffee, rest up etc.
It’s those that took advantage of Disney in this case that forced their hand
Disney by far has the longest lines of any park I visited. When even dang Busch Gardens is increasing capacity and moves their lines more smoothly, you know you have a problem
I agree with the substance of your post BUT how does does Disney have concrete numbers of DAS users who are also going to wait in standby lines while waiting for their call back time? Nobody scans into standby