Do you really want your IOT devices to be directly addressable on the internet? It's my understanding that having devices behind a router is safer. I go a step further and disable UPnP on my routers and everything still 'just works' including network printing.
You supposed to control access with firewall, and controlling security is much easier when computer/device has a routable address.
Though, IoT devices should probably be restricted of any Internet access based on their security track record (but again, this is orthogonal to being directly addressable).
I still don't see a reason for the average consumer to have a static, reachable IP for their devices. I see privacy concerns but no advantages.
I have a gigabit fiber (to the home) connection which terminates at a device with 4 Ethernet jacks. They all work, I've tested connecting directly to them with a laptop, but I plug a router into it and all devices connect through that router instead. It's the 'stateful firewall' aspect of using a router that I want for improved security. https://en.wikipedia.org/wiki/Stateful_firewall