The thing that defines performance of DRAM is AFAIK the capacitor of the bit cells and not the transistor driving it. And also AFAIK the process to create those

The thing that defines performance of DRAM is AFAIK the capacitor of the bit cells and not the transistor driving it. And also AFAIK the process to create those capacitors is quite unique to DRAM, so you can't just go and use a "logic" process unchanged and produce DRAMs.