Also, as the article mentions, Go 1.18 can now inline functions that contain a "range" for loop, which previously was not allowed, and this would contribute performance improvements for some programs by itself. The new register-based calling convention was extended to ARM64, so if you're running Go on something like Graviton2 or an Apple Silicon laptop, you could expect to see a measurable improvement from that too. (edit: the person you replied to confirmed they're using Apple Silicon, so definitely a major factor.)
The Go team is always working on performance improvements, so I'm sure there are others that made it into the release without being mentioned in the release notes.