Japanese consumer protection regulations are believed to be the underlying reason
So we've seen 13 of the likely 16 Grass cards from this set (we still need numbers 1-3 Meganium Copium!!)

This gave them an air of "grandeur" and "preciousness", and practically every set started to have their fill of these cards.EnergiesThey also became a part of this set as secret arts, but they had a golden border, which would also classify them as "Gold Full Art"."Common" EnergiesIn block order:1) In Sun/Moon: Base Set (S/M 1): Psychic Energy SUM 162 and Metal Energy SUM 163.2) In Sun/Moon: Guardians Rising (S/M 2): Grass Energy GRI 167, Lightning Energy GRI 168 and Fighting Energy GRI 169.3) In Sun/Moon: Burning Shadows (S/M 3): Fire Energy BUS 167, Darkness Energy BUS 168 and Fairy Energy BUS 169.4) In Sun/Moon: Crimson Invasion (S/M 4): Water Energy CIN 124.Special EnergiesWe had for the first time a "Gold Full Art" version of Double Colorless Energy GRI 166, in Sun/Moon: Guardians Rising (S/M 2)!Besides, in other sets, like Sun/Moon: Crimson Invasion (S/M 4), there were two other cards in the record:Going beyond, in the Sun/Moon: Ultra Prism (S/M 5) set, we also had another pair:Following the same reasoning as the Unit energies, the third copy appeared in Sun/Moon: Forbidden Light (S/M 6):Next, in Sun/Moon: Celestial Storm (S/M 7), the special energy, Rainbow Energy, was reprinted in this rarity

III Exile this Saga, then return it to the battlefield transformed under your control
These kinds of decks can usually justify a lower land count