Well, I cannot image any reasonable tech person who actually uses macos for the past 10 years " would say using a powerful macos unix-based workstation is not a UNIX workstation.
My M1 Mac Studio is amazing. Yes, it's UNIX but it is also much more. I can see why a "purist" might discount Apples version of UNIX, but personally I have never been a fan of "purist thinking", as it is too narrow, in my view. YMMV
At macOS's core is a POSIX-compliant operating system built on top of the XNUkernel,[76] with standard Unix facilities available from the command line interface. Apple has released this family of software as a free and open source operating system named Darwin. On top of Darwin, Apple layered a number of components, including the Aqua interface and the Finder, to complete the GUI-based operating system which is macOS.[77]
am mulling which model to ask santa to get me for xmas (santa == me) to replace my trusty ol 15" retina mid-2014 macbook pro ... if i go top-end i could fly to the states and buy it still saving few 00£'s !
You should definitely move to the latest Apple ARM chip technology.
I have an M1 which works very good and I'm very happy with it; but it I was going to make a new purchase, the latest M* ARM tech would be very nice to have.