What stops anyone from just mining it? Cryptocurrency mining may or may not be profitable at any given time, but it doesn't matter that you're spending $7 to mine $5 worth of cryptocurrency if you're willing to pay the $7 to get the VPN.
Meh, perhaps now, but there is an easy pipeline of work (mostly menial, Turk type tasks) for crypto that runs right past KYC. Cash for crypto is also surprisingly easy to find, again bypassing most KYC.
Far simpler, if you're a teen that wants to get around the block, to just have an older looking friend do the video selfie.