Re: I don't get it!
"The Optane branding seems mis-leading considering all the previous Optane marketing has been for a sort of permanent RAM" thingy."
No. "Optane" brand meant Intel/Micron generated flash that had (and still has) superior latency to any traditional NAND flash. Optane also doesn't degrade in performance even when the drive is full; it doesn't require TRIM (or Secure Erase) that NAND relies on.
You are speaking of NVDIMM's (DDR4 socketed Optane) which - in a limited way - still is the highest performing local storage there is because the memory is by far the fastest interface of a CPU. Only Intel and Micron produced Optane storage, and Intel paired this with only Xeon platforms to win more server sales. (somewhat like limiting RDRAM to Intel chipset back in the Pentium 4 days, with no clear benefits for users at much higher prices. We all know what became of that)
Aside from NVDIMM's, Intel 7th-8th gen CPU chipsets' software RAID feature (RST) had support for a small (16GB-64GB) PCIe M.2 Optane module to act as a r/w cache for a single HDD. At this point many users already opted for SSD storage in which Optane produced minimal to no benefits with added complexity. Cost of the module+HDD drove people to just buy an SSD.
Intel also sold PCIe cards (900p and others) and later on proper M.2 NVMe SSD's with Optane flash. At some point they also sold hybrid Optane cached QLC flash drives. (QLC = slow crap)
Optane failed because the low latencies and IOPS numbers offered by traditional NAND is already enough for most businesses; NVDIMM's are expensive, small in size, require software support and other hw considerations, they eat up the precious memory slots, and only benefited some HPC applications.
Had Intel&Micron licensed the Optane tech to other companies, it could have changed the game.