about the only way to justify the Mac Pro is if you're irrevocably committed to FCPX, Logic or other Mac-only software
I assume you're counting macOS in this "Mac only software" category?
My work is all about writing code, tooling, infra etc. Most of the technologies and tools are cross-platform/standardised, and most of the production runtimes are a Linux distro.
Some of the apps I choose to use
are macOS-only, but there's generally a workable alternative on other desktop platforms (e.g. think Sequel Pro vs either MySQL Workbench or HeidiSQL etc, Kaleidoscope vs.. some other Diff tool, etc).
So, of all people I could absolutely use an alternative platform for my workstation. In some cases it would give more options than I have now (e.g. running native container solutions without a VM). In some cases it would give me less (no legal/straight forward option to run macOS VMs).
But none of that is going to make me drop macOS as my preferred workstation OS, while I can still be productive with it - be it a high-spec Mac mini for a couple of years, or a constantly-upgradable Mac Pro for quite a bit longer.
Yes there are more hardware choices if you don't make macOS a hard requirement. Not necessarily
better choices, but definitely more. If those choices work for someone else, that's great, go and buy it and be happy. But don't pretend that there's no inherent benefit from macOS itself.
Ok, so I'm just obstinate you might say? Yep probably. But let's look at the financial aspect.
The base Mac Pro is ~$6K. Even if the competition were *half* that price (which it isn't, for comparable specs), any extra downtime due to Windows or Linux above 40 hours (yes, one "contractor" work week) over
the lifetime of the machine, and it's cheaper for me to just buy the Mac Pro, and not have those headaches.
Yes, if you do the math, you'll know what I charge clients per hour. And if you do, you'll notice it's not really that high. The more a person earns per hour, the less hours of downtime before the Mac Pro is cheaper.
Yes, it's unlikely most people would just buy and use the base Mac Pro. But arguing about speculative prices is ridiculous.