The Verge's article[1] mentions that the consumer version planned to be a few years out won't have silicon carbine lenses, and that those lenses are responsible for the majority of the cost of the Orion device due to extremely poor yields. Sounds like they're pretty great otherwise so maybe they're return to it at some point in the mid-future.

I agree regarding the undertaking - enormously costly, but if they can make it "just glasses" it might actually end up as the "next computing format" Zuckerberg was looking for. (Even in that case though, whether it was worth the investment/Meta can stay on top I don't know.)

[1] - https://www.theverge.com/24253908/meta-orion-ar-glasses-demo... (ctrl+F for "silicon carbide", it's the last mention)