That's not really possible. You need fish and fishing mechanics, you can't just create a game where fishing happens to be possible without anyone having thought

That's not really possible. You need fish and fishing mechanics, you can't just create a game where fishing happens to be possible without anyone having thought about it. You would basically need a life simulator for that, with rules like fish exist, fish live in water, fish chase other organic things in the water, a worm attracts fish, the hook makes the fish stick if it bites, do you see what I'm saying? You can't just have all this stuff happening organically. It's possible to have systems where the possibilities are so vast that the dev can't consider all of them, like spore or path of exile or whatever, lots of games with lots of options for customization. But you can't just have a real world simulator, the real world is too complex to simulate, let alone in real time.