Again, this is your own bias rooted in the fact that most SV/tech people in bay area think you have to launch a product as soon as possible and that's the only way tech has ever been developed. It's not the only way, and the agile model that works well for web stuff and consumer/B2B applications often isn't suitable for other kinds of technology development, where there is a custom hardware component.
If you want to see a lightfield display you can just visit Display Week (http://www.displayweek.org/). Once you see one in person your doubts will be put to rest.
I've noticed that the agile model doesn't work well for a lot of technologies too. Things that have been well studied (for example, creating a webapp with X frontend and Y backend, or creating a graphics engine with DirectX) have known costs and estimates. There are answers you can look up on StackOverflow. Not all realms of technology have such luxury.
Is there an alternative to agile that's available out there?
I am not sure that agile is the right term for what you are both describing.
It doesn't mean releasing things before they are ready. Agile is about potentially shippable increments and customer collaboration. Again this doesn't mean testing in production.
While the manifesto was written for software, with minor changes it can applied to most industries. Even with hardware, agile principles can be used to iterate on design, not necessarily physical production.
If you want to see a lightfield display you can just visit Display Week (http://www.displayweek.org/). Once you see one in person your doubts will be put to rest.