For varying definitions of "open source" (a considerable amount of functionality is offloaded to binary blobs in many models).
In terms of duplicating effort, in the page linked it specifically states it's based on Cerowrt, which is in turn based on Open WRT (which is actually FOSS, instead of just in name).
More importantly, it doesn't say "...Help Us Build an Open Wireless Router Firmware" because that's not the goal of this project. As you clearly pointed out yourself, and as they implied in the post they made, that's already been accomplished multiple times over. The goal is to make a router designed for the Open Wireless movement, which is why, in the first sentence, they link to https://openwireless.org/
They could even help support their project by selling routers with open-source firmware already installed (if allowed by the manufacturer).
The current firmwares are kind of stagnant (considered good enough I suppose).
The idea of does everything for me, including updates and minimally secure are disjoint ideas - you can't have security unless you have complete control over your own device - and OpenWRT with luci already provides that. Relying on a third-party to do your updates, even if it's a trusted body like the EFF is always open to attack.
OpenWrt doesn't provide the self-update by default, and I hope it never decides to add such thing, unless we get reproducible builds, and build some kind of network consensus to verify the integrity of packages, and that they were derived from specific source code (as Nix/Guix and Debian's ReproducibleBuilds are attempting). In other words, we need to remove the centralization of updating, because it's such an easy target for the likes of you know who.
Also, you know what else is such an easy target for the likes of you know who? Unpatched systems.
I've been using Tomato for years and DDWRT is also available. (only using Tomato because my current router status for DDWRT is "Work in Progress")
Both are open source, compatible with most routers, and have a nicely developed user interface.
http://www.polarcloud.com/tomato
http://www.dd-wrt.com/
https://openwrt.org/
http://www.polarcloud.com/tofu
Maybe updating the title of this post would help with the confusion. "...Help Us Build an Open Wireless Router Firmware"
I'm all for competition and alternatives to products, but developers might be able to better allocate our resources rather than create a clone that might not be necessary. Such as ensuring existing projects are secure.