USPS continues to bleed money but that's due to the mandate from Congress about pre-funding pensions. That's a requirement that nobody else has - see the articles about the 3rd-largest coal company declaring bankruptcy and shedding its pension obligations.
Is always understaffed? Yeah, there are lines a lot of the time. So go to USPS.com if you can and buy postage online. Go to the offices that have ATM-like machines if you can't. My usual problem is that I have a letter that I don't want to send Priority Mail and I've gotten out of the habit of having 10 different amounts of postage labels.
Misplace the mail? I signed up for their service that sends me a picture of almost every piece of mail that gets delivered. The last problem with the mail that I can remember having was dropping off a check at the airport while leaving on a trip. The contractor suggested that mail there got extra inspection, which delayed it. I'm not sure that's right but I can see somebody dropping something "bad" in the mail right before they leave the city/state/country.
They're certainly not perfect and I bet it's not any more fun to work there than when "going postal" was a thing. But I'm pretty happy with USPS.