I had a Palm Pilot when they were the cool thing and connectivity was the biggest issue. Syncing had to be a deliberate process, which meant it didn't necessarily happen frequently, which meant that things like calendaring and even news weren't really all that useful.

The iPhone came out just as WiFi had become pretty ubiquitous and a reasonable data plan was something that could be negotiated. And, even so, you could argue that the iPhone didn't really take off for a few more years.

(The iPod before it had a somewhat similar trajectory. It wasn't obviously a game-changing device from day one.)

ADDED: Connectivity was an issue with the iPod too. It didn't matter that much for music. But anything that required timely updates, such as podcasts, didn't work as well.