~1TB ram servers have been at market for about 18mon-2 years now. Just nobody is buying them because of their extreme price. Most companies especially smaller machine learning start ups can't exactly justify ~$30k-$50k+ in a single server when doing something off in the cloud is way cheaper (generally).

Either way you can swap to SSD's for 4 orders of magnitude cheaper.

:.:.:

Only a few large multi-nations have jumped on them, and mostly they just stick 20-30VM's on them to crunch data internally.