Point being the structures and underlying workings of FPGA doing things vs an ASIC are really different. A person who can FPGA-prove something can't necessarily put that specific design on a 350nm node. Surely not on deep sub-micron. The FPGA won't even run by itself in the development configuration. Stand-alone FPGA boards with the stuff flashed or whatever is closer to building some hardware. It's still only a subset of skill required, though.