What they have is good enough for competitive DDR5 DIMMs.

In China they already make integrated circuits with a finer pitch than at TSMC or Intel before the transition to EUV.

This is achieved by multiple exposures, which increase the fabrication cost, but with the current prices they still have very healthy profits.

EUV is only required for highend ram like HBM3E, HBM4.

they seem to be doing fine regardless.