There should be other ways to obtain the Field notes.

[Wegente]

Your logic is flawed and incomplete. RNG of this magnitude should not be acceptable. Gaming has changed over the decades.

If you complain about this kind of RNG you should also ask SE to remove RNG from other content like Big Fishing or Triple Triad cards, because it's the same for those. You could farm those for months as well without ever seeing them drop.

And there are some kinds of fish you can attempt to get only once every few real-time days (or weeks even iirc) because they're gated behind certain weather conditions which have extremely long respawn timers.