Seems like you think people catch lake sturgeon to eat them. This is a very rare thing these days. Sturgeon fishing is almost always catch and release. This doesn't mean there aren't any fish killed. Any catch and release is quite stressful and might kill one. But people aren't just eating them and sturgeon are quite robust. And there's certainly no commercial fishing for them like the issues with ocean/marine ecosystems you're describing.
At least in Wisconsin rivers/lakes you cannot legally keep any sturgeon with the normal fishing license. You have to pay an extra fee to keep 1 (per season). And according to the statewide Wisconsin statistics only 5 sturgeon were harvested from the St. Croix River in 2025, and a total of 58 were harvested across the entire state.
Years again I was gifted a sturgeon fishing trip on the Fraser and I still feel bad thinking about it. In hindsight knowing how much we stressed and probably harmed that animal. What a cruel way to entertain ourselves.
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.