4x64gb is already a lot of RAM for a consumer during the ddr5 generation. Even with a 16 core processor with SMT that's 8 GB each for 32 threads. Any larger and it starts to really hurt latencies that consumers actually vie for.

(Typical) servers however have no problem with memory latencies as long as you throw in more channels to compensate with bandwidth. They don't care if the primary task gets done asap they care that 1000 tasks can get done asap and that the db is all in ram.