Plus what that means for diet-- nowadays transportation is a bit faster but I met a guy from the midwest talking about how 30-40 years ago they didn’t really see much fish if it wasn’t frozen and fried.
In the US, the vast majority of all commercially available seafood has been frozen. You are just paying a defrosting fee for the more expensive “fresh fish” in the display case at the market.
I knew all fish for raw consumption had to be frozen but I didn’t realize most other fish was as well. Either way, this dude was saying he pretty much only saw fish sticks growing up.