Or other tablets. There's a lot of good ones out there, and they are popular enough.
Handspring and Palm sold millions of devices, and so did HP/Compaq, while Apple couldn't get traction earlier with the Newton. There's no real technical reason why the Newton was destined to fail, just as the other devices ascended and then fizzled out. There are network effects at work, society has to be receptive, and the price has to be acceptable.
> There's no real technical reason why the Newton was destined to fail
Which reinforces the survivor bias, doesn't it? Often the product theories are more "look I succeeded once, so I did it right and you should copy me" and less "I was at the right place at the right time, the technology was there and society was ready for it".