If you count the box topper, there are actually four different Charizard singles related to this issue: the regular holo, the reverse foil, the box topper, and the non-holo version that was available only in the Lava theme deck
Its way too much of an investment to spend three mana every turn
Why that is remains a mystery as it is hypothesized that Ghost was supposed to be super-effective against Psychic, but instead Psychic was immune to Ghost-types(which were only one family and had terrible moves to work with, in addition to the Physical-Special not happening yet.) However since all Bug-types were weak to Psychic-types in some manner or other, this didn't come to effect, and Psychic-type remained supreme, while Bug remained a gimmick
But what of the Pichu card
That's because it's generally good for the strongest deck in Standard to have to change up some cards with every set to keep the metagame fresh