When I last renewed my passport, I did it in person. They did require that I show proof of imminent travel. Without it, I suspect that they would not have taken my application.
The previous renewal was by mail. If I recall correctly, I got the new passport in about 2 weeks, despite not having paid for expedited service.
Both experiences were perfectly satisfactory. The mail renewal was about 12 years ago, though, and the demand for passports had increased considerably since then, so even without COVID it’s entirely possible that the processing times have increased. I would leave a couple of weeks extra for a mail renewal these days.