[Ratiofarmings]

Because unless your applications need to store lots of things in memory, it doesn't matter for performance. macOS is very good with memory management, so for a lot of use cases 8gb is simply sufficient. The system as a whole is a lot faster than the '15 Air.

That being said, the lowest config is often something that is just there to meet a price point for advertising purposes, not what Apple actually expects people to buy. They've been doing this for decades. 16gb was the "standard" in 2015 already for most machines.