[mellinoe]

Even most technically-minded people still use QWERTY on full-size computer keyboards despite it being a terrible layout for a number of reasons. I really doubt a new, nonstandard keyboard would get much if any traction on phones.

[aaronax]

T9 was fine for typing and probably hundreds of millions of people used it.

[heleninboodler]

It only worked because it had to, given phones just had keypads back then. As soon as qwerty-with-your-thumbs was available, everyone abandoned T9 and never looked back.