I personally only fish to eat these days. And I still sometimes feel bad about hurting them and ending the lives. I comfort myself knowing that most fish I catch are not very intelligent and that it is certainly less torture and a better life than, say, a factory farm pig with very high intelligence. And since I am doing the killing myself I do it quickly and minimize suffering. I know whataboutism isn't a strong argument and in no way refutes your point about catch-and-release fishing enjoyment coming from the fishes' struggle and suffering (in what capacity it has for this).

I accidentally caught 1 smaller (~meter length) sturgeon while fishing for the very tasty walleye (fish). I certainly enjoyed the "fight" in which the fish was suffering and it didn't really occur to me at the time. But I did return it to the water quickly.