macbook air, is no good for programming.
sketching and frontend things yes, but when you start running environments within it like docker for example. it will crash.
The use-case is “quickly write tiny JS/PHP/Html programs”. I do that on my Air. I have never used docker and don’t really know what docker is besides a tech-de-jour.
If you spec it out to about 2000$, with the i7 upgrade, 16 GB of RAM, 1TB SSD, I'm pretty sure it will be plenty powerful for the majority of developers. Probably as good as the 5 year old MacBook Pro everyone still uses.
Yes, you don't need Docker for the development environment. I do that sometimes though for convenience and for projects that I develop on only now and then.