I doubt the PCI solution is “yet to be announced”? The cost argument strikes me as an arbitrary assessment since it’s very hard to compare this figure against any other, even for equivalent hardware. Longevity is a factor here. Given that Thunderbolt is effectively PCI on a wire, and that macOS supports external GPUs now, you can already get reliability and functionality with a Mac Mini.
The issue is getting the same power, expandability, and degree of future-proofing. Then there’s Intel ME and what-else-lives-inside, and for that I find the T2 encryption and boot restrictions to be a good thing. In the age of Huawei making the news, I’d prefer a company that walks the walk on privacy, wouldn’t you?
I submit to you that this new machine looks to me future-proof for a decade. If you’re not happy about the cost it could be that it’s not aimed at you. I don’t have the budget for it but I distinctly remember laptops and workstations costing $10k, and it does not surprise me, and I’m not unhappy about it. Is it my type of Mac? When I can afford it, yes. And until then it’s still a yes, except I can’t afford it.
But it’s not an unreasonable price point.