Alas I took the MBA back and got a refund and grabbed my spare Thinkpad T440 out of the cupboard and put windows 10 on it. The OS is a shell to run Chrome, Excel, Word, Putty, iTunes, kicad, LTspice, WSJTX and I use Fastmail for mail. Literally nothing gets in my way. It just works. And everything like photos and videos are in FILES not weird opaque containers and buggy as crap apps. The CPU is about the same speed, I've got more RAM in this, it's got a FHD display which is good enough and the keyboard is amazing compared to anything Apple had to offer. Plus it cost me literally 1/5th of the cost.
Also comparing OSX to windows, you can actually mostly drive windows from the keyboard without resorting to hand warping shortcut combinations reminiscent of Megadrive Streetfighter cheat codes.
I think after switching back I just had stockholm syndrome.