I came here to say exactly the same thing. I'll go one step further... not only are the equipment/fabs fully depreciated, but they are 8" rather than 12" and so

I came here to say exactly the same thing. I'll go one step further... not only are the equipment/fabs fully depreciated, but they are 8" rather than 12" and so none of the new equipment/processes will work with them. It's a huge fight to even get anything older than 90-110nm in 12". That is why the relatively high volume, but very margin constrained, display industry is stuck at those nodes. It doesn't make sense to build and bring up a new fab with new equipment at margins below 30%, but the entire industry is built on that cost structure. Further, a lot of the designs for older processes have been iteratively improved (yield, performance, etc), but the older models (simulations) for them are insufficient to design new chips without explicit reuse or iteration. They are effectively stuck on that node at that foundry, unless they want to incur significant (opportunity) costs.