> Reliable NAT traversal on top of wireguard is their moat

And a damned good one at that. I can spend five minutes on a (family) nontechnical user's device and set it up to be able to access the parts of my network it needs to get to, and it's easy enough to use that I can walk them through the troubleshooting over the phone if it ever goes awry. Regardless of where they are or I am.