And most shops likely aren't using a JVM new enough to use records, and it will be a while before they are able to upgrade. And even then, most 3rd-party libraries out there won't use records, because they want to be compatible with the JVMs their users use. Hell, most popular libraries available on Maven Central are compiled with JDK8, or, at best, JDK11.
Aside from immutable instances, it would be nice if 'final' was the default, as well.