Do they make DRAM? I thought they made compute chips mostly.

If I recall correctly, RAM is even more niche and specialized than the (already quite specialized) general chip manufacturing. The structure is super-duper regular, just a big grid of cells, so it is super-duper optimized.

They (GF) do not make DRAM. They might have an eDRAM process inherited from IBM, but it would not be competitive.

You’re correct that DRAM is a very specialized process. The bit cell capacitors are a trench type that is uncommon in the general industry, so the major logic fabs would have a fairly uphill battle to become competitive (they also have no desire to enter the DRAM market in general).