Psychics can be confusing in a way. They have a LOT of power on the television show. And also in the show, they seem to be absolutely unstoppable. Not so in the cards. They do NOT really on power in the cards. They rely mainly on special abilities and Pokemon powers to take down their opponents. A wonderful example is a very sought after Pokemon, Mewtwo. If you look at a the Base Set Wewtwo, it has two attacks. I am going to focus primarily on the second one.
Barrier. It attack states that if you discard one psychic energy, you can prevent all effects of attacks, including damage, done to Mewtwo. This absolutely blows away the other Pokemon people always though of as the perfect staller, Chansey. Discard one energy, and your immortal for one turn. That's very good.
Overall that certain Mewtwo has no overwhelming attacks whatsoever. But his defense is abnormally useful. What I'm trying to say here, is that 85% of the time, Psychic Pokemon will use abilities that annoy and plunder your opponent in an unbelievable state of disgust (pardon my brainiac language).
That's not the only tech that psychic Pokemon have. They don't have high HP. The absolute maximum HP that a Psychic Pokemon has is 90. I'm not sure about the sets yet to come but of the cards we have now, Psychic HP isn't very high. Many Stage 2 Psychic Pokemon average about 80 or less HP.
=Psychic Pokemon don't usually have overwhelmingly powerful attacks without a price
=They don't have HP any higher than 90
There you go