You have a car . . . you can charge your phone using a MagSafe car charger mount, which I have in all my cars. If you're working and have an office, you most likely have an iPhone charger set up at your desk, at least I did when I used to work before retiring.
My point being, you don't have to function strictly on the battery all day long when you have opportunities throughout the day to charge up your device when opportunity to do so presents itself. I don't see any need to get silly over having to add a MagSafe battery pack because there are people out there saying doing so defeats the look or "purpose" of the having the Air to begin with. To me this is absolute nonsense.
No matter the device, if you find yourself running low on your current battery charge, then charge it up. Simple as that. I also use my 13 mini and right now at 6pm it's charge level is sitting right at 79% charge level. Yes, I have ready access to a charge point for my devices I'm using. Yes, I have no problem slapping on a MagSafe battery pack if needed to charge up my device. For me it is what it is.
The battery health on my devices I daily are typically greater than 95% battery health including my 13 mini which had a brand new battery installed recently. I still prefer the form factor of the Air and the compactness of my 13 mini. I enjoy using either device for what they are, imperfect iPhones, but they both work very well for my use case.
I just shake my head when I see people get all worked up having to "ruin" the look of their iPhones or "defeating the purpose" of having a thin or compact iPhone by having to use a case or MagSafe battery pack . . . whatever . . . Just enjoy the iPhones you have. Not all people have the same priorities or use case and that is also okay. This is just an observation I have noticed on the forums regarding thin and compact iPhones yet you have those who actually use them and appreciate what these devices have to offer their iPhone experience.