Restricted delivery doesn’t do identity verification. I can say I’m John Doe and sign as John Doe and receive the package (I’ve received restricted delivery packages before and the carrier in multiple different states never asked for ID). I’ve also sent restricted delivery mail before and never had my identity checked as OP claimed.

Edit: Per Stamps.com [0], the USPS “may” require ID on delivery, but again, in my experience, I’ve never been asked once.

[0] https://stamps.custhelp.com/app/answers/detail/a_id/157/~/re...