Do you think you'll realistically need 3 TB RAM to run a sufficiently good model 1 to 2 years from now? I certainly don't. Considering what can already be done with 128 GB of relatively slow unified memory, imagine if efficiency improvements continue apace, the memory becomes 128 GB of HBM, the flash device becomes capable of sequential throughput matching today's DDR5, and such a system was affordable as a routine purchase for the average person.