First, that doesn't make sense when there are full modern system boards that sell for a fraction of that individually.

Second, why would you need something different that what routers are already doing? They are just trying to sell their own openWRT routers, the hardware has existed for a decade at or below $100, why would it be difficult for them to meet that?

They aren’t just trying to sell a router, they are trying to make available a fully open router without blobs right from boot, that is unbrickable, and selling it essentially at cost

Where are the numbers here? How does what you are saying connect to what is being talked about in a concrete way? You are talking about software and saying it has to cost $100 or more while there are $30 routers on amazon.

https://www.amazon.com/dp/B082HH24YY/

This is more or less discussed in the link. They started looking at BananaPi products as a starting point, but have some requirements that existing boards don't fulfill. One in particular that probably precludes all of the $30 boards you're talking is:

"that this router isabeautiful (sic) example of excellent GPL/LGPL compliance"

These routers are crap. Anyone who cares a tiny bit about their wireless connectivity won't buy this. And I don't think OpenWRT wants to associate their name with "low-quality" routers.

What you are saying here is speculation. Most router's shortcoming is software. I've used cheap netgear routers with openwrt and they work incredibly well.