I have a MacBook Air 2012, and have been waiting to upgrade for... 2 years already. The laptop will probably end up being 10 years old by the time I upgrade...
- crappy webcam,
- no built-in SD card reader (a 1TB SD card is ~200$, and my music does not need to be stored on an expensive SSD)
- magsafe.. if this was the only downgrade, I'd upgrade, but TBH I love magsafe on my mac and I would miss it if I upgrade.