They have controls as most of these folks have to have (background checks, access controls, physical security, etc [1]). Still better than randos pulling your mail out of the mailbox in front of your residence imho. Its a shim until the last of need for paper mail gets deprecated, as I still need to receive correspondence of importance via snail mail (business filings, IRS, etc).

[1] https://www.sbimailservice.com/security/

(all commercial mail processors you consider should have similar controls in place, make sure you ask!)

Some people in my area use these services and I've considered it because mail theft is a big problem in my area. Organized rings doing package theft, identify theft, and all that. So for us at least, it seems significantly safer than having it delivered directly. Personally I just go paperless as much as possible and have the post office hold my mail (another popular response).

If you want a less expensive 'lite' option, you can sign up with the USPS and they will scan your incoming envelopes and email you the images. This at least alerts you when something that should have made it into your mailbox, doesn't.

PO box?

The problem with PO boxes, besides being in short supply, is all the places that can't accept or ship to PO boxes (DMV, voter registration, private parcel services, insurance companies, ...)

While it cannot be used as an option for "your physical residence.... in legal documents" -- voter registration or the DMV -- the USPS does offer "Street Addressing Service." It provides a street address you can use with UPS, FedEx, and others. P.O. Box 59 would be 500 Main Street #59 (for a Post Office located at 500 Main Street). The service is free. (I just filled out the form two days ago.)

Why? That's a federal offense in the USA at least. If you're afraid of that, you may as well fear any mail delivery person.

The fear is understandable, as mailmen don't open and digitize your correspondence. It's a new risk, however small, that you have to consider.