tl;dr Call your member of Congress or Senator if you need help getting a passport appointment.
When we renewed our kids' passports in October 2021, it only took a few weeks for their new ones to arrive in our mailbox. Trish and I sent our passports for renewal in late November, expecting a similar quick turnaround. I received mine back a couple of weeks later because I'd forgotten an essential item - the check to pay for it. Trish didn't receive hers in December, so she set up an appointment at the Colorado Passport Agency. We're very fortunate as this office is just seven miles away from us.
The only appointment Trish could get was on the same day as our flight to Cabo San Lucas in early January. Her appointment was at 9am, and our flight was at 11:25am. She found out during her appointment that she didn't receive a new passport in December because our dogs scared off the delivery driver. She'd ordered expedited delivery; that's why they tried to deliver to our front porch instead of dropping it in the mailbox.
The passport office was able to turn things around quickly and she arrived at the airport, new passport in hand, at 10:45am. 40 minutes wasn't enough time, according to the checkin counter, so she had to reschedule her flight for the next day. This was unfortunate since we waited at the gate for 45 minutes due to delays.
Mexico was fabulous.