HAMR, MAMR and mechanical HDD trickery
Well, you can't blame the HDD manufacturers for trying to stay in the game. HAMR HDDs have been in development for more than a decade, and you still can't buy one. MAMR HDDs are exotic, and you won't see them for sale for a long time either. HDDs with dual actuators have been tried before and abandoned. Maybe it can be made to work, but adding electro-mechanical complexity to HDDs can only be a source of new HDD failures. In the meantime, caging electrons in NAND flash is a quicker way to increase capacity dramatically. Niche markets for HDDs will hang on for maybe another ten years, but when those use cases can be challenged by NAND flash storage, it will be the end for HDDs. The storage imperative in the 21st century is maximum capacity with minimum power requirements. Anything that does not do that will not be around.