Its not though. For consumer computers somewhere 1k-4k there's nothing better. But for the price of 512gb of RAM you could buy that + a crazy CPU + 2x 5090s by building your own. The market fit is "needs power; needs/wants macOS; has no budget" which is so incredibly niche. But in terms of raw compute output there's absolutely no chance this is providing bang for buck
2x 5090s would only give you 64GB of memory to work with re:LLM workloads, which is what people are talking about in this thread. The 512GB of system RAM you’re referring to would not be useful in this context. Apple’s unified memory architecture is the part you’re missing.