Can't use rangefinders on the PGA tour to get probably the most important information a golfer needs. This sport involves animals and fair chase needs to be considered. You can't hunt with a drone. Those provide real-time feedback on the exact location of the prey from a distance, sound familiar? No previous iteration of fish finders meets that standard. Traditional sonar requires you to be directly over them to see them, and side scan let's you see them once and you've got to go back to the spot or fire a cast knowing where they were at that instant, but not once they've moved.
It improves the ability to catch fish. That is detrimental to the population either through increased harvest, or much less so in the case of catch and release due to increased accidental mortality. This is a big topic in musky fishing since they're not as hardy and vulnerable to delayed mortality. They're lowering panfish bag limits around here. Since the guides and guys with FFS clean up, the average guy who doesn't catch a limit nearly as often can't keep as many when he finally gets it right when the stars align.