VRAINS does things a bit differently
Ps: 3reyes is not legit, they do not have license and should not be on the list, the company who had the license was called Navarrete (produced in Peru and distributed to many latin countries like Mexico, Argentina, Colombia, etc) who mostly produced sticker albums like Merlin Stickers did in Europe but also released a series of cards refered to as armables (buildable) as well as a series of pokemon postcard sized cards
Today, fans still enjoy all pokemon from generation 3, all pokemon generation 1, all pokemon generation 9, and all pokemon generation games, while many collect all generation starters pokemon, every generation pokemon starters, and each pokemon generation starters
While some Pokemon spike in popularity when a single chase card is released before fading back into the pack, Mewtwo has produced genuinely valuable, genuinely sought-after cards in Base Set, the Wizards-era Gym sets, the ex era of the mid-2000s, the EX era of XY, the GX era of Sun and Moon, the V/VSTAR era of Sword and Shield, and now the modern Scarlet and Violet era
One cannot possibly lump all these decks together as one when discussing sideboarding plans, but I think that its more or less okay to do so when talking about strategic basics when discussing playing against this kind of deck