Japanese chefs are so much closer to their food. But to me this is like butchering a small animal in front of you and serving it up to you raw. Is there value in this?
Cruel. But less cruel than to sink the animal in boiling water. (Or equally cruel from the point of view of the crab).
I don't believe invertebrates experience pain in a way we can meaningfully understand. To my mind the crab was killed humanely.
Some sushi-ya serve shrimp considerably more alive than that crab goes to the table. The tails are peeled, but not broken off, and the diner eats the animal while it is still alive. Others do lobster in a similar way. The tail meat is removed from the tail, sliced and returned, but it is done so quickly the animal is sufficiently alive to continue moving its legs and sometimes even try and walk. The idea is that living shrimp (and lobster) taste different and better than those which died even moments before service.
Seeing other people eat live food doesn't bother me at all. It does bother my wife. When I go to sushi-ya which do live, I don't take my wife. Regrettably, I can't take you either.
In case it needs saying, while I've arrived at a different conclusion, I respect your position on this.
I don't like raw fish (even shushi) or watching my meal live just before or during my meal (don't take me either boar d laze), however, that video seems tame to me. Doesn't seem out of the norm for preparing any other protein type. Preparing chicken seems more brutal.....I don't watch that either, but I sure eat it when it is presented and prepared.
Anyway, when crabs eat fish (and they do) they eat them alive. And certainly not with a precise cut of a sharp knife. They simply devour the fish with no ethical concerns.
I think there is a cultural difference at play. This came up last time when someone saw octopus "writhing" around when lemon juice was squeezed on it. Maybe some of it is show, but a good deal of it has to do with ensuring that the seafood is fresh. The octopus was dispatched, felt no pain whatsoever from the lemon juice (the reaction was purely chemical) but an octopus that is not fresh will not react that way. We are accustomed to smelling and looking at seafood to gauge freshness, they just take it a little further.