My wife and both applied for new passport books on the same day via normal processing, and received them both on the same day:

04/13/19 - Applied in person at USPS.
04/17/19 - Application status available online.
05/15/19 - Email received stating passport is printed. States delivery via Priority Mail should be by 05/21/19. Subsequent emails on same day give tracking number, and change delivery date to 05/22/19.
05/20/19 - Passports received. Tracking showed passports were originally scheduled for 05/18/19, and even got to local town that day, but didn't make it on final delivery truck until 05/20/19. Birth certificates also delivered 05/20/19, in separate envelopes, via regular mail.