It really doesn't. In virtually every case the work is being completed faster than the cache can grow to that size. What little gains are being realized are from not having to wait for cores with access to the cache to become available.
If your tasks don’t benefit then don’t buy it.
But stop claiming that it doesn’t help anywhere because that’s simply wrong. I do some FEA work occasionally and the extra cache is a HUGE help.
There are also a lot of non-LLM AI workloads that have models in the size range than fit into this cache.