I think it's something like this.

If you're performance oriented, and like overclocking, or hitting higher benchmarks/fps above and beyond the actual real world "value" they give you, CUDIMM can be worth it.

Or if you're in a certain workload professionally/hobby where it actually helps it can be worth it.

Or if you are in some kind of other/gaming scenario, where you are CPU limited with a 4090/5090 or something, it can be worth it.

For instance, if you are spending $5,000 on a PC, or doing something very cost inefficient like Custom Loop, CUDIMM on a 285k is probably a better value than something like that. It's a better performance value than RGB. Some people like paying out the ass for "looks". Some people like paying out the ass to see 1-5% higher numbers on the screen. To each their own. But no, you don't need CUDIMMs.

Also, I'd add that Intel currently has a "multitude" of problems according to spokespeople from the company itself. So, the microcode and bioses and stuff are probably going to be changing quite a bit in the coming weeks/months. Could in theory make the current benefits CUDIMMs provide be even greater, or be smaller. So, just realize there is a chance you could see the gains cut in half or something potentially, if they release changes that alleviate a bottleneck that shouldn't have been there, that CUDIMM helped bridge, but now it's no longer as much of a bottleneck, so CUDIMM doesn't have as much impact.