It had mostly come down to 3 (Samsung, SK Hynix, Micron), but the Chinese manufacture's market share is growing rapidly, especially as they ramp up due to sanctions. CXMT is currently 10% of global DRAM, having seen previous YOY growth of 1%->4%->8%. YMTC is now global #3 in NAND.

It wouldn't be surprising to also see Japan make a comeback in memory - they are investing heavily (both privately & government) in semiconductor manufacturing.

For now, there are only 3 that matter, but the reason is purely because the US government has sabotaged their competition as soon as it became apparent that the incumbents would lose market share.

Without what the US government did and still does, the prices of memory would have never increased so much and all the world would not have been forced to pay so much for memory.

I also like to keep prices high for as long as possible for the things I sell. I bet most people I ask would answer the same.