You are deliberately not answering the question.

"If every person that ate fish was out there...." exactly - they purchase fish caught commercially because either they don't know how to catch their own fish or they don't have access to catch their own fish (access either with time, money, or physically). Commercial fishing solves that by precisely doing it "at scale a lot more efficiently" as you pointed out and ships the fish to where people will purchase it.

I didn't ask "what if everyone went out and did it themselves"

I asked your thoughts on people who DO fish for themselves, or those using traditional fishing practices.