But that' exactly the thing, Haruka. In Gen 1 there was only one special stat and it covered both special attack and special defense. Alakazams had an incredibly high special stat and they were fast. Psychic types were only weak to bug and ghost attacks, and the only bug type attacks that did damage were too weak to make a difference, and even then the only pokemon that could learn them were still slower than Alakazam. Ghost moves, on the other hand, there was only one and that was nightshade, which has a fixed amount of damage. The only ghost pokemon in the game had poison as a second typing, making psychic attacks super effective against them. The only way to stand up against a psychic type in Gen 1 is with another psychic type, and whichever one has the higher stats or better luck (critical hits) wins.
I've never been a fan of psychic types. My favourite was always poison. My Gen 1 team is: Jolteon, Golbat, Rhydon, Hypno, Arcanine, and Dewgong.
Though, I like my Gen 2 team better, even if it only has 5 instead of the usual 6. Typhlosion, Slowking, Ampharos, Hitmontop, Crobat.