I can understand that the project doesn't want to support ALL the devices out there. Especially if the performance isn't up to par.
BUT:
I'm running Kodi just fine on a Zero 2 W. It's not overly responsive but it works. And as soon as something is playing i don't experience any low performance issues at all. AND the RasPi is directly powered by my TV without blocking an additional outlet.
Just install DietPi!
Installing Kodi and setting it up to autostart is REALLY easy. Konfiguring everything to your needs is almost as simple as it is with libreelec.
I wouldn't recommend an alternative OS here if the project did support the Zero family. But i feel there is a (small but justified) demand for Kodi on these devices. DietPi does get the job done in a convenient and unbloated way.
If you have a Motorolla Atrix Lapdock, there is nothing better to put them into good use than connecting a Pi Zero 2 W to it.