I would agree that the main design of the sit down, counterbalanced, internal combustion engined forklift hasn't changed much since it's initial debut, but just because the design hasn't changed I wouldn't say there hasn't been any development.

A few things have been tried & proved to be worth the investment
(the Hyster/Yale monotrol pedal,steer axles w/power steering cyl's mounted, etc come to mind), & a few things have proven themselves to just be a good thought, but not commercially viable (the ole' Hyster Mono-mast upright-3 wheeled pnuematic trucks). Change is inevitable & the market always steers the way.

I think the lesson to be learned over the last 100 years or so is that end users of forklifts will always favor the least expensive, most durable forklift available. Back when Toyota & Nissan broke into the US market, they were ALOT cheaper & just as durable as the American brands of the time. Now that the playing field is again full of highly functional durable lifts, with each one being "premium" in one way or another, there's again room for a less expensive "standard" lift- the question is- will the players in this field be as "durable" as the premium models they're competing against- again- time will tell.

As far as the comparison w/phones- thru clever marketing the phone has become a necessity which you now can't live without. The players will always change based on the new widget. Combining a phone w/ a computer was a success & whatever company thought of it clearly outdid it's competitors- for now.

I'm not quite sure how this scenario would play out in our industry- don't know what you could combine a forklift with that would be a benefit for the end user- especially one they would pay for.