Neither, T9 was pretty reliable and fast. That was the best method for most people.

But if your goal was to be above the average speed, the probability, even low, of false prediction by the algorithm would make you lose « a lot » of time while with no T9 your error span is scoped to one character.

Plus, for the people who typed without seeing the screen, you couldn’t take the risk to accidentally send the wrong word that would totally change the meaning of your message while an error on one character could be understood by your recipient.

But for the average user who just wanted acceptable speed, reliability and used its phone while watching the screen, T9 was the best for them.

speed of the lookup was not a limiting factor and felt instantaneous. the problem was more short words for which there were too many suggestions and a bad or non existing ranking system and missing words in the dictionary. very similar to swipe keyboards but more precise and faster