For gaming, if you're willing to put in some effort with setup, you can put like 1,000 games on it very easily from NES, SNES, Genesis, Arcade (using FBNeo), etc. with RetroArch. Just download the roms online and copy them over with a USB drive and basically have RetroPie in your Mi Box.

Horizon Chase is ANOTHER proof how shit these Xiaomi boxes have become

It used to work JUST FINE right out the box on the MiBox 3 (the one I have)

After several updates it just don't work anymore and as you said no matter what it's broken

I had the same joy before the mandatory updates and after that only downhill

Mi Box 3 and 3S are great devices.