The UX might have turned out a little bit different but the smartphone would have been pretty much the same thing. My opinion is what permitted the existence of smartphones wasn't Apple but superior mobile hardware & mobile data tech which was emerging.
Those PDAs looked like this because their only business model possible was note taking for business uses because of pricing issues, mobile data issues and processing power issues.
But was anyone else besides Apple seriously considering releasing a device with no keyboard and non-horrible software/UX (admittedly of course the first iPhone was probably closer to a toy than a real "smartphone")?.
Windows Mobile barely changed in the 10 years after Pocket PC was first released. I don't think hardware limitations were the main cause of that. Microsoft (or rather the faceless design committee) simply had no imagination and were more than happy to see their market share grow by 10-30% every year in a fast growing market (well.. who wouldn't?).
Back in 2010 I had a HTC HD2, hardware wise it seemed to be several years a head of iPhone 3GS/4 but for some reason it was still running iPaq software.
Sure and that's why they had a first mover advantage but I wouldn't expect that first mover advantage would have lasted more than 2 years if they did not attempt it.
> I don't think hardware limitations were the main cause of that.
Mobile processing power really sucked and 4G only got released in 2009. Resistive screens were also pretty unusable before that.
Those PDAs looked like this because their only business model possible was note taking for business uses because of pricing issues, mobile data issues and processing power issues.