Just a quick point of reference. I am currently waiting for a call back from Delta regarding travel I want to book in September. I am a Platinum Medallion member, the second highest possible level, and called in on the dedicated Platinum Medallion 800 number (not the general 800 number). The initial wait time was 60 minutes, and I chose the call-back option.
If Delta is still having 60-plus minute waits, for their higher tiered loyalty customers and with all of their "Best" awards:
Delta Named Best Overall Customer Service Airline
then I think that's indicative of the entire travel and hospitality industry still struggling to get their feet back underneath them.