One thing I've been thinking about lately with emulation: why can't we replicate and use the original hardware more easily?

There's lots of knockoff console replicas out there, so it seems like the chips can still be manufactured. Wouldn't it be fairly cheap to build a board/chip that contained either the original chip designs from classic computers/consoles, or hardware-level emulated chips? Seems like you could stuff several of those retro chips onto a single expansion board. Then emulation software could tap into this "emulation expansion board" to make use of the real chips. Is this all crazy talk or does any of that make some sense?