They got rid of the % operator for error propagation for one.

That's funny; one selling point of rust is the easy propagation of errors thanks to the '?' but zig removed the % which was the equivalent I think

The operator wasn't removed, it was replaced by a keyword. See the documentation on error handling: https://ziglang.org/documentation/master/#catch

You can still propagate errors in zig using ? like in rust. they just simplified it