I see all the memes about guillotines for the rich, funny in spirit, but actually building one in the town square is not practical. They take a ton of materials, they are huge, and they do not even work reliably. Would it not make more sense to build one from metal with hydraulic pistons or something? I am not a machinist, but a more mobile unit you could wheel into a square to decapitate a few effigies seems about as effective for sending a message, and easier to remove or relocate if needed.
I like your approach here of making a clearly wrong statement just to get more activity on this important topic
I will add yet another comment that guillotines are neither complicated nor require much material. you could make a sturdy one with less than a dozen 2x4s, some screws, a scrap piece of rope, and whatever junk metal you have lying around that’s around 24x8 (which you need regardless of how fancy the frame itself is)
that said, mobile ones seem like they would also have a purpose