what the refiners have done for the last 40 years has been to just build out existing refineries. They are many times the size today that they were when they were built.
refiners have found it cheaper to do it that way.
With all the stacks of epa rules/regs/requirements, you are correct. I did hear of a new facility being built in AZ but haven’t followed up to see if it actually ever was or is in the works.