Wouldn't the delivery company get worried that a lot of packages for different addresses are attached to the same phone number and received by the same guy?

+1000 sats. It's important to have a place to pickup mail, especially if you can't receive mail at your home or work address and if general delivery/PO boxes require government ID. A mail forwarding service can provide privacy, but if you don't have a place to physically receive the mail (last-mile), it can't help.

A network of KYC-free PO boxes, package pickup stores or parcel lockers could solve this: https://anarkiocrypto.medium.com/second-realm-ideas-caebc787d791 As you describe, the business would advertise their services as a PO box location and set a fee, the customer would send the package to this address (with a pseudonym or include their email/phone number in the address) and the business would hand over the package on confirmation of the pseudonym or a PIN sent by email/SMS + payment of the fee.

In some countries, there are already KYC-free PO box services that only require a phone number, no government ID. Similar to DHL lockers or UPS Stores. But these are restricted to specific couriers and may only accept national packages (no letters or international mail).

A taxi service could help, but you would still need to address the package somewhere. If it's general delivery, the post office may require government ID that corresponds to the name on the package. Unless you talk with the taxi driver in advance and they provide the shipping address?

I read somewhere about how you can have your packages shipped to any post office by writing “General Delivery” under your name, and the address of the post office, and you don’t need a PO Box to do it. They hold the package at the post office for you / for a period of time / and you pick it up there. Perhaps you have to show them an ID when you pick it up. I’ve never tried it so I can’t elaborate on the process. Obviously the post office would be aware of your name and the return address listed on your packages, and your facial biometrics would be captured by the web of cameras installed in the post office, but I think this basically solves for the issue you’re asking about (?).

But what about the cameras inside the place where you pick up the package?

Or do you walk in wearing a balaklava?

See what Arcade City (decentralized uber) is building. It would enable this. An individual who will receive your package for you then delivers it to wherever you want to meet. Sender doesn't know you, and if you meet somewhere, driver wouldn't know your identity / location. You could even request the driver do a dropoff where you never even meet.