It all stems back from the very first set, the Base Set, originally printed in English in 1999 - the big red lizard had the most hit points (HP) at 120, making it the toughest Pocket Monster to take down, the highest damaging attack (Fire Spin for a whopping 100 damage) making it the hardest hitting Pokmon without a drawback (were looking at you Chansey with your Double-Edge attack) and had the best resistance, it resisted fighting types by 30 damage, it also has an alluring and unique Pokmon Power which essentially meant any deck could run a Charizard, if you had one
Incapsula incident ID: 679000170039686231-148318251706156114
Neither mode is great
As with many affinity style cards he allows for ridiculous starts but is more frequently a poor top deck later in the game
Sabrina will allow you to pull your opponents Pokmon out if it poses too much of a threat, while X Speed allows you to do the same with yours
Add to all of this the fact that the card has no retreat cost, and you have one of the most impactful cards in the competitive meta for the Pokmon TCG