One of the many problems was trying to limit the use of Optane to Intel devices. They should have manufactured and sold Optane memory and let other players build on top of it at a low level.
This.
Optane died because Intel wanted to kill AMD and ARM with it. Killed Intel and a great technology along with it.
> Optane memory
Which “Optane memory”? The NVMe product always worked on non-Intel. The NVDIMM products that I played with only ever worked on a very small set of rather specialized Intel platforms. I bet AMD could have supported them about as easily as Intel, and Intel barely ever managed to support them.