Please, don't mention ancient history that has no relevance for today's functionality. That's the same as if I was evaluating Windows 8 on the basis of DOS.
Of course the first iPhone was unusable for me -- I never bought it! Instead, I bought my final Windows Mobile phone at the time, an HTC device (even more expensive than iPhone in those days), and suffered through its use. As I've been saying, default Apple software as a rule is awful; iOS devices without advanced 3rd-party apps would not be an option for me.
As to
tablets, which is what we were talking about, I insist on my original statement: iPad 1 was a
productivity device for me from Day 1 when it first went on sale in Europe in 2010 when I bought it. The apps "universe" was already well developed in those days.