This issue is not specific to anglers, people can bot camp any high q node and they absolutely do. q300+ bears and whales and you name it. They are botcamped, reported on discord and abused.
A hard and relevant fix that would obliterate the unfairness of this across the board would be to make animal quality nodes migrate/reset/reshuffle across the world every week or so.
I've said it 100 times, it makes zero sense for animals to infinitely spawn in the same place over and over again forever, no animal would continue to venture in to an area that is hunted so often, especially not the strongest and smartest and highest quality of animals???
1 small change would 100% fix the issue immediately.