Even with a 5" screen, it was bigger than for example iPhone 17 in every single dimension due to its hefty bezels (and not insignificantly so; iPhone 17 is closer in width to iPhone 13 Mini than a Dell Streak).

Screen diameter is in general a bit misleading figure for phones from different generations as "full screen" phones tend to have a taller aspect ratio and hence larger diameter even with same body dimensions.

Only a little bigger but you're right, I didn't think the bezels on the Streak looked that big but I see they're really pretty substantial. It's the dimensions of a modern 6.5" phone, basically.