Ironically, that was largely because it let you more easily use sites built for desktop, due to the larger screen space and ease of pinch to zoom. Those older phones would have been somewhat more useful if mobile first/responsive sites had been a thing then, but it took the popularity of the iPhone for that to happen.
Then people started sideloading and basically showed Apple they needed a store which they quickly came up with. Getting an application on the other two platforms at the time was mind numbingly bad (activesync was to put it mildly awful to use). In some cases you needed to get the carrier involved (better have a few months to validate and a few hundred thousand dollars to pay for it).
Also that screen they used was way better than what any other phone out there had at the time. Most of the top end phones needed a stylus and itty bitty keyboard to be any sort of useful.
I would say it was not until the droidx came out that anyone had anything that approached how cool the iphone was.
I think Blackberry was the only one that did both OK enough to take seriously. I know people loved the Sidekick, but I never used it and don't recall if people used a web browser on it, or just text messaging.
The first iPhone was more impressive than a Blackberry.
So it did even less than I gave it credit for.
That's part of my point. There was a tremendous amount of hype for something that was incredibly limited and objectively bad. However eventually it became very good and took over the world.
So it was even worse than I remember.