The typical Hello World implementation tends to reveal very little about the language, because their print/println/printf/whatever implementations have failure modes that are either impossible to handle or easily ignored (e.g. panicking, throwing exceptions or returning error codes which you can implicitly ignore without compilation error) which they frequently use to effectively hide the complexity inherent to the problem. Some examples of this:

The C Programming Language includes a Hello World example that calls printf without checking the return value and returns a success code from the main function regardless.

The first example I find when googling "java hello world" simply calls System.out.println and neglects to call System.out.checkError to see if it was successful before exiting with a success code. Some Java developers won't even know what I'm talking about here because it has never occurred to them that printing may fail in a way that can only be discovered through this weird checking mechanism.

Go's example from their getting started guide simply calls fmt.Println while ignoring the return values which include any error that may have occurred, and the program exits with a success code regardless.

The example from Rust by Example is at least correct and thorough in that it will predictably panic upon error when invoking the println! macro, which is documented, but will through that mechanism not give you the option to actually handle the error except by using a different mechanism which front-loads more of the complexity (e.g. writeln!(io::stdout(), "Hello World")? for something equivalent to the Zig example).

Of course for something as basic as Hello World it might be easy to tell whether it was successful through a quick glance at the output, but consider some of these limitations in a larger program.

So maybe there is more inherent complexity to this problem than a typical Hello World implementation will reveal. Add to that the complexity of Zig's new swappable I/O models and their Hello World isn't so absurd.