Why build your own cloud and hire a ton of specialized personnel to manage a bunch of infrastructure you're not in the business of managing when you can buy this one time purchase from Apple?
Why wait around for your project to render when you can render it in real time and make changes as necessary? Remember when you had to wait 30-45 seconds for Xcode to deploy a new build just to see if your UIButton is the right color? Doesn't that suck?
The Mac Pro is for professionals, just like the Bugatti Veyron wasn't meant to be a daily driver. Sure, some rich enough consumers will get it just because they want it, but that's not the reason it exists. Anyone who makes enough money to transition their hobby into their profession won't scoff at a $10-45k price point. Truckers buy $100-200k trucks because they depend on it for their livelihood. Plumbers, electricians, etc. all buy $30-40k vans for the same reason.
The reason this computer looks so out of place on the pricing charts is because we've gotten so used to cheap $400-800 laptops that we forget there was a time when mainframes cost dozens of millions of dollars a pop. Nowadays, that market only matters to Fortune 100 corps, but it's still real and thus there's still a real demand for beast machines like the Mac Pro.
Because I can scale the cloud as much as I want. I can purchase 100x the compute power of this Mac, and I stop renting it as needed. The Mac Pro will need to be upgraded over time, the cloud will automatically upgrade what HW I can rent.
Also, there's a difference between rendering previews and rendering in real time. This machine is not going to render a production frame workload in real time. You do that kind of stuff with offline rendering. A machine that's 4x faster represents a marginal increase in workload that can be rendered in real time, because 3d rendering isn't O(n). And if you want real time rendering previews, there are PC workstations that will still smoke this Mac.
I feel like once again, people are trying to justify Apple pricing by appeal to edge case, when the reality is, people can put together a professional PC workstation for 3dsmax that performs about the same and costs half the price or more.
Look at the Z8 for example, not even the top of the line custom built PC workstation: https://petapixel.com/2017/09/13/hp-z8-pc-can-upgraded-insan...
Up to 3TB of RAM, 48 TB storage, 56 CORES, and this was shipped in 2017! Starting price $2400 (vs $6k for new Mac Pro). And you can't even get NVidia cards for the Mac Pro. An NVidia RTX 2080 or Titan RTX can be up to 2x faster than a Vega II Pro in DCC apps. If you want really fast rendering, Nvidia has actual racks of GPUs that are far more cost effective than sticking 4 expensive Vega II Pro's into this Mac.
A fully decked out Mac Pro is likely to cost $36k. An NVidia RTX Rendering server, which can give you real time desktop previews and contains 8 Titan RTX cores with 24GB VRAM, and 16 Xeon Cores, also costs $36k, and it can be scaled as needed.
If you really need to scale up massively parallel workloads, then commodity compute HW is far more cost effective and less limited.