Back in the early days of the pandemic (I'm thinking it was April 2020), I had to call Delta to change a reservation since taking a trip as a tourist would have been a waste of time asnearly everything was closed (I couldn't change it on-line because of the discount code I'd used). Of course, since nearly everyone was cancelling/changing their flights at that time the wait times were crazy long. Since the Delta system is 24/7, I waited until close to midnight Pacific time to call (3am in Georgia) - got through in less than 30 minutes.
A few months later when I had to call back and change my change (since Covid was still going strong six months after the "two weeks to bend the curve" Delta had instituted an automatic call-back system which worked quite nicely.