And it'll be another 5 years before JDK21 becomes a widespread target for production and then another 5 years for the new features to be accepted in code reviews. Culture changes slowly.
We took way less time to move from Java 11 to 17 compare to the 8 -> 11 migration due to the change in deployment methods: instead of deploying jar file and run it with the server-provided JRE, we now use docker to ship our app + JRE to server.