Phones aren't stolen for the phone, they're stolen because carriers enable the theft. There's a reason why thieves now cycle around on e-bikes and grab the phone from your hand, and the reason is premium rate phone numbers and shortcodes. They want the phone unlocked because they start texting as many SMS shortcodes (that they control) as they can, siphoning thousands of dollars worth of purchases off you.

If you make the mistake of not notifying the carrier immediately, which you won't think to do because everyone thinks the phone was stolen for the phone itself, you're on the hook for the charges.

Carriers know that no legitimate users use (or even know of) shortcodes, yet they have them enabled by default on all plans, exactly because they take a cut from this theft and they can turn a blind eye to it by pretending the charges are consensual.