I think Nokias 7650 deserves also mention. Launched in 2001/2002 it arguably laid the foundation for mainstream smartphones, while Communicators were inevitably doomed to be niche devices. 7650 had also many of the hallmarks of modern smartphone, at least compared to Communicators which were more of evolutionary dead end.
Worked with someone who had a 7650. Watching what that could do blew me away at the time. First phone I saw that genuinely acted like a PC in your pocket. Bought a 6600 as soon as it was released and loved it.
You could probably make an interesting article on how much a modern smartphone in 2021 differs from the 7650. Fundamentally I don't think it's as much as many would think.
