Why can't I catch big fish when I cast the net with one finger?

Does the questioner want to ask "Why can't I catch big fish if I keep casting the net?"

The net is cast shallow.

Big fish swim in places with relatively deep water levels, so if you cast the net shallowly, you won't be able to catch big fish.

The cast net is also known as the swing net, the rotating net, and the hand-thrown net. It is a small conical net used in shallow water areas. It is cast out by hand so that the mouth of the net is downward. The pendant is used to quickly bring the net body into the water and use it with the net.

The rope connected to the edge is slowly retracted, allowing the fish to enter the net bag and pull it out of the water.