USPS delays

Just going to point out that it's currently peak season for the USPS. Everyone and two of their brothers are shipping or having something shipped this time of year.

Also, money orders are the same as cash. You don't just decide not to sell them because it's a PIA. They're accountable. Honestly, they're not that tough to deal with. Easier than processing a certified letter. A clerk in a post office didn't delay them. That came from a lot higher above them. Of course, you only see the clerk, so it must their fault.
If you knew this branch you would know for sure she just didn't reorder them when she ran out. She is the only one in the branch. And it's her responsibility as the postmaster of the branch to reorder them. In rural branches of this size there are no "clerks" just the postmaster. This happened prior to "peak" season. With all the people that work from home or have ebay stores postal money orders are essential to their business. Money orders are not the same as cash. You can't take one addressed to gunbunny to walmart and buy a case of beer. You can take any 50 dollar bill and buy one. She only became "accountable" when complaints were filed above her head. It may be different where you live.