To put it another way, one person who seemed like a reasonable real world reviewer stated that his Air had about 20% left at suppertime, which made him uncomfortable - battery life anxiety.
CNET’s review seemed to come to similar conclusions, at least during the first several days.
But then they had to qualify that by saying that a couple days in, once the battery life normalized, they would end the day with around 40%.
So it very much seems to be something that can vary, depending on how new the phone is, if it’s still indexing, etc.
Personally, I’ve pretty much noticed the same thing with every iPhone that I’ve ever owned going back to the 5 all the way until my current 15 Pro Max…
On day one, the battery can last me all day, maybe a day and a half to two days.
After a while, no matter how good the battery was on day one, no matter how big the phone is, no matter if it’s a regular or a Pro Max, it will at least need to be topped up once at some point during the day.
I expect the Air to be pretty much the same, last a full day the first several months, until it eventually needs to start getting an extra boost halfway through the day.
And I expect this to be true with the 17 Pro Max as well.
It’s interesting because this is definitely something I very much would have cared about several years ago, but at this point charging is so fast and so easily available between MagSafe, USB-C, battery packs, battery banks, etc that it doesn’t really bother me anymore.
Even the “20% by supper” feels fine to me, because if I plug the phone in and I start eating, by the time I’m done eating it’s likely to be back at 60-80% and last me just fine for the rest of the day.