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.

That's not really true though, and I know this from personal experience in the company that I work for.

We have a fairly large development team all using MacBook Air, the previous version. It's a little workhorse, but you gotta know its limitations.

It struggles a little with Java development (i.e. running NetBeans or IntelliJ), but the new version (i.e. 2019 model) will do that just fine.

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.

Bonus: you get a function key row

You don't need to run docker for every single thing

Depends on the environment. You can easily run Docker containers on the new Air.