[nicebyte]

but dynamic DNS is a thing. I've had setups for it since god knows how long, though admittedly not on my phone.

[ben-schaaf]

Dynamic DNS takes setup for every single device, and obviously doesn't work for devices that switch networks frequently. It also doesn't help you if the IP is behind a NAT.

[rklaehn]

DynDNS does not work for devices behind a NAT unless you manually set up port forwarding.

Iroh gives you the connectivity of DynDNS without any manual configuration.