Sorry for late reply, I am mostly travelling during summer this time and not behind any PC.
In short, Xeons-W and Threadrippers Pro (sadly only Pro exist in current generation, and the pricepoint is identical to Xeon-W) are worth it if the money isn't objection.
You primarily only get 2x multi-threaded performance and that's it for most people but that's still a lot. Even mainstream platforms are now capable of 192GB ram (4x48GB, recently introduced modules) and that's as much as most people need, although it's not easy to get it to run stable. Most people also don't need to run 4 GPUs anymore either. So it comes down to diminishing returns of paying more to get more.
Threadrippers 2xxx and 3xxx were the ultimate blend of both (performance and good-value, although my 3990X was already questionable at 4K per CPU) but sadly that's not available in current generation.
Right now, the highest core models from Xeon-W and Threadripper Pro are amazing workstations if the value proposition is sound for you.
Even I would hesitate to pay it though.. mainly because I am no longer really limited by multi-threaded performance. Majority of my work, is done slowly because I am slow person :- ).
Really, all about money. If I were a single artist, I would probably get the best (Xeon/Threadripper) each time. Likewise, if I were bigger studio with high margins (The Boundary, DBOX, etc..).
It's the in-between small studio where I would question who needs top-tier multi-threaded machine and who will get by absolutely fine with just using 13900K or 7950X. Because not everyone is primarily doing lot of rendering. Everyone who is primarily spending more of their time on editing some part of scene, or post-production, etc.. absolutely get mainstream platform only.
