They don't have the infrastructure to meet global demand.
Depends on what kind of memory you are talking about.
For DRAM, CXMT were only 1% of the global suppy 3 years ago, and are now already 10%. They are growing extremely rapidly.
If you are concerned about consumer memory - smartphones, laptops, desktops, then this is what CXMT are making. CXMT do make HBM too, for AI accelerators, but their volume there is held back by sanctions.
They're 10% of the market now, and they've shown the ability to scale up manufacturing rapidly. They certainly won't singlehandedly meet demand, but they might at least be able to temper the price growth quite a bit.
Yet. Maybe they will by 2028, making this prediction incorrect.
I would never bet against a Chinese company ramping up production quickly.