Apple introduced variable refresh rate back in 2015. That’s over a decade ago, I’m sure there’s some new tech involved here, but quite the omission.
What's new here is the 1 Hz minimum.
But to the rest of the world variable refresh rate existed for years by then. As is with most Apple "inventions".
In this case the patent goes back to 1982: https://patents.google.com/patent/US4511892A/en