Why? They are copying the complete EPCS content to the *.jic file.
Like I mentioned I haven't used Quartus tools in decades, so I wasn't sure that there was a way to read a EPCS in system with the only connection to the EPCS being the FPGA. I was mistaken in remembering that the tools would not allow reading the entire EPCS. Or perhaps I'm thinking of a different vendor, as I've used products from every FPGA vendor that exists at one time or anther since the Xilinx 3000 family.