We Homo Sapiens make physical contact with our outside world with our hands.
Fish make physical contact with their outside world with their mouths.
The mouth parts of fish are soft and could easily be damaged.
Netted fish never have damaged mouth parts.
It follows that the mouth parts of fish must have evolved to have very effective pain sensors if they are to avoid damage.
It follows that angling for fish with hook and line must cause severe pain to the caught fish.
Angling for fish by hook and line must therefore be considered a cruel sport.