As someone who shopped between the Air and 17e, I was looking for a lighter phone, I feel like the 17e is still a better phone for like people who are looking for a phone to be a phone. I almost got the Air but went with the E cause of bigger battery, and better speakers, and it's weight is really close to air.
If I was a person who didn't have access to an iPad Mini, I'd probably got the Air, but, I really don't use my phone for much, other than brief sessions of connectivity.
In the end though I have no buyers remorse, cause of how little I rely on my phone, The weight and battery size matters more to me than thickness. If the air had a beefier battery, like around, 4000 like the E, I'd went with it overlooking the awkward thinness and mono speakers.
However, on days where I am out all day, and have a lot of calls, texts, video conferences and other notifications and things I really can't rely on my iPad mini for, the constant micro sippage of battery on my 17E really makes me appreciate having the larger battery.