The original iPhone was many thing but certainly not blazing fast. And yea, many people said it not that great now but this is the future, most of the reviews if I remember correctly.
CNET: https://www.cnet.com/tech/mobile/original-iphone-review/
Ars: https://arstechnica.com/gadgets/2007/07/iphone-review/16/#h1
> “ We love the concept of the iPhone. It's extremely easy to use and almost entirely self-discoverable; the interface looks better than any other phone—smartphone or not—currently on the market, and it's just plain fun to use.”
> “However, we are not buying something else either; we plan to wait to see what software (and hardware) updates might come out for the iPhone in the near future. We believe that the iPhone is cool enough to wait for whatever might come out, and we have confidence that many of the nits we have picked can be fixed through a major software update.”
I remember very frequently switching back and forth between my iPhone and Android or Windows Mobile devices.