There is also quite a bit of flaw in your logic as well. The iP5s has a smaller battery (1560mah) and the G2 larger at 3000mah with the screen size difference being also smaller for the iP5s and larger for the G2 it makes sense they have the same browsing (with screen on time) battery life over wifi.
And why wouldn't one choose a larger screen is not a valid argument, as some prefer different form factors. Me personally I usually like the smallest footprint, but the battery life won along with my already substantial investment into Android apps helped me stay with Googles offerings.
I don't think the logic if flawed at all, but it is subjective. The G2 has a larger screen. I'm not saying anything other than a generalization about why wouldn't you use the larger screen all other things being equal, in this case we are only looking at the single factor of wifi browsing that keeps being brought up as a positive for the iphone 5. The iphone 5's battery may be more efficient, BUT it's still a moot point because all things being equal, the larger screen is more advantageous, especially if you are wifi browsing on a cell phone screen for 10 hours!
As for why you would choose a larger screen, it's a very valid argument, but it's certainly subjective. But I was only microscopically honing in on the single point of wifi browsing times, that's what keeps being harped on here. Certainly other things can be taken into consideration, considerably more video play for example, or how about 23.5 hours of cellular talk time, or 3g browsing. I understand the small size of the iphone attracts some, it attracted me for years, but that was not the argument.
The specific argument was how the battery life on the G2 sucks and how the iphone 5 has so much more battery life.
I mean, if you are not wifi browsing for long periods of time then why bother to even put this up as an argument? The guy arguing the point that the iphone has better battery life pretty much just picked out the single thing that the iphone came close to the g2 in (but didn't beat) and that was wifi browsing, ignoring all the other stats showing the G2 trouncing the ip5 , using that as the basis that the G2 battery life was horrible.