We see two very different Post Offices. Fort Wayne is still a primary sectional processing center. South Bend has been relegated to under-class status.
Speaking in generalities:
When you mail something, it goes to Fort Wayne for processing. If it is 467/468 local, it gets processed and delivered next day, mostly. If not, it goes to Indy for further processing. Mail going TO Fort Wayne comes into town and is delivered (mostly) the same day.
Say you mail a letter to your next door neighbor (before 5PM). It will get picked up that day, taken to Fort Wayne, processed, returned to the delivery station, and delivered the next day.
South Bend does NOT process outgoing mail anymore. It goes to Fort Wayne, or sometimes Indy. There it gets processed with everything else in the stream. If it is going back to South Bend, it has to be trucked both ways. That takes time. Mail going TO SB goes from Indy to FW, gets processed, then goes to SB. SB used to process its own incoming mail. Now most of that gets done in FW, delaying everything by a day.
Say I mail a letter to my next door neighbor (before 5PM).
Letter gets picked up in Bourbon, and trucked 28 miles to South Bend (SB). South Bend puts it, and everything else, on a truck for an 80 mile ride to Fort Wayne (FW). If FW can get it processed, it will be sent back to SB the following morning, generally too late for processing that day. If FW can NOT get it processed, they will send it on another 100+mile truck ride to INDY. That will get back to SB then next day, guaranteed too late for processing and delivery that day. It is not unusual for me to mail a birthday card with my local (joke) processing center, and have it take 5+ days to be delivered. Even if all goes well, my letter to my neighbor goes (28+80+80+28). If things go wrong (Postal), add two 100mile trip to/from Indy to the ride. On a bad day, my letter to my neighbor can travel 416 miles. That ain't getting done overnight. Considering drive time and processing time x2, there is no such thing as overnight delivery here.
If I remember correctly, the last two price adjustments for first class stamps was downward. I use USPS for shipping primarily because it is convenient. I can print a label at home, and arrange for package pickup next day. It has gotten progressively more expensive. Too much so, I starting to think. But USPS has to make some money to stay in business. Standard Mail (formerly 3rd Class, aka Junk Mail) has been a loss leader for decades. USPS loses money on every piece, but it generates cash flow. First Class mail has dropped off so much in the last 10 years that USPS has considered eliminating Saturday delivery, and every other day rural delivery. The public blows a gasket at either suggestion. Yet nobody (USPS or public) pays any attention to delivery standards. If you (the public) don't pay any attention to how long delivery takes, why does it matter if it comes on Monday or Tuesday. Stupid. I'd settle for once a week delivery. Nothing the USPS handles is urgent.
I hope the FRTSB is handling my retirement funds well. My USPS retirement is about 25% of my income right now.