I don't follow JAI but maybe Jonathan Blow should try zig, it's a great fit for game development and I remember him mentioning that he wants a language that is fun to write in.
zig is following pretty much different path from jai afaik. zig prefers everything explicit and is very verbose whereas jai has many implicit things and also has macros or something similar. Anyways, more will be seen when it is released.
Maybe you can enlighten me, but from my view it seems the biggest difference is that zig exists and jai doesnt (yet?); at least for practical purposes.