Sadly, over the years, psychic-type Pokmon have become less and less powerful, but they were incredibly strong in the base set
Prior to being fought - by the entire cast except those four - he made several "appearances" by having his personality energy through Yuya during extremely stressful or high-pressure duels - essentially giving the audience a Final Boss Preview to showcase how ruthless, violent, and controlling he is during duels
This gives the card a more premium look
This three-drop 2/1 flyer dominated play early on for all of those reasons and is still great today in all of the brews
Additional Info from direct source/owner of these cards: Starter Trio were also given out at Worlds 2022 in London
I just think Synchro/XYZ/Pendulum etc have taken the magic out of the game over the years, as often duels are won in the first turn