The landing page says SIMILAR to Java. It doesn't say runs identically on exactly all versions of every system that Java programs will run on.
Also, this is a C binary we are talking about. Fundamentally, a C binary will not run on multiple architectures (at least not without some sort of special translation mechanism like Rosetta or qemu user-mode emulation).
"Modern desktops and servers" is still pretty much x86-64 for most of the world. Yes, I know there are ARM servers and I'm typing this on an M1 Mac and I own nearly all kinds of Raspberry Pi's (even the minor revs of some models).
The C machine model doesn't dictate native compilation. You could (and in fact IBM OS/400 does[0]) compile C to a binary format that does run on multiple architectures.
Maybe instead of "C binary" you meant "C compiled to native binary", but that linguistic shortcut also encourages a mental shortcut that excludes several interesting design tradeoffs. In the IBM TIMI case, the equivalent of setting the execute bit on the binary triggers OS/400 to perform the native code generation and save that native code to disk, similar to some versions of Android Runtime, but without mandatory garbage collection.
