When I was a carrier, I had a business road on my route, all the mailboxes were at the curb for every business. On two or three separate occasions, I’d get to the last box and it looked rougher than it did the previous day. Business owner came out and told me the box had been broken into again, along with several others on the road, and wanted to know what we could/would do about it.
I called my postmaster and explained and asked if USPIS would be getting involved (as the business owner also asked). I was told no, they don’t get involved in those sorts of things, the owner would just have to file a report with the police, and we’d stop delivering on Saturdays since none of the businesses would be open.
I never got a further explanation than that, so I couldn’t say why USPIS doesn’t get involved, but they don’t seem to anymore. 🤷♀️