Zebrafish are an extremely powerful model for drug development and toxicology.

Sure. But there’s also a reason we don’t do in silico molecular dynamics, test toxicology on zebrafish, and boom done drug is on the market. Even extremely close organisms, with LCAs much earlier than the zebrafish, can have wildly different reactions to potential drugs and dietary elements.

There are things you can feed a chimp but not a human.