The “net” is more than just which to keep and which to throw away. Jesus was saying that the net gathers in all of the fish, good and bad and then the fishermen sort those worth keeping and selling/eating and throw out those that are not worth keeping. And He goes on to say “thus it will be at the end of the age, with the angels doing the sorting of those who are good and go to heaven and the bad are thrown into the fires of hell.
From Matthew 13: 48-52
Again, the kingdom of heaven is like a net thrown into the sea,
which collects fish of every kind.
When it is full they haul it ashore
and sit down to put what is good into buckets.
What is bad they throw away.
Thus it will be at the end of the age.
The angels will go out and separate the wicked from the righteous
and throw them into the fiery furnace,
where there will be wailing and grinding of teeth.
And this separating of the good and bad is seen in again in his parable of the wheat and the tars being separated at the threshing.
Yes, I understood that.
One doesn’t wish to be thrown out, but being sold and eaten is no great deal for the fish, either ...
(Yes, I know, it’s just a limited metaphor.)