One could still freeze it like sushi fish to get rid of at least some of the pathogens.

One would think so, but it turns out, not really — the big concern in sushi fish is usually parasitic worms (like anisakiasis), which are live multicellular organisms that don’t survive freezing.

In chicken, beef, and pork, the concern is typically bacteria (like salmonella, and e. coli) or parasite cysts (like trichinosis), which are not killed by freezing.