RB is scientifically accurate, the future will be only jellyfish and the birds that eat them. This has been known since before the games released and the theory has had more research and validation since then. This also explains the motives of Team Aqua and Magma and their solution to the jellyfishication of the oceans. You get some of the most varied and least varied routes by design.
https://faculty.washington.edu/cemills/jellyblooms2001.pdf