The Java programming language and the Java Virtual Machine (JVM) are known for being very stable and favouring compatibility over new language-level features.
This focus on stability arguably is one of the reasons why Java is so popular with larger companies, particularly those of the enterprise variety, where reliability, maintainability and a long-term outlook are key and typically more important than the latest and greatest features.
However, starting in 2017, with the Java release cycle changed to rapid 6-months iterations, from the previous 2-years cadence, updates to the core Java language and the APIs Java provides have become much more frequent (without doing away with stability; there are still long-term support versions that’ll continue to receive updates for 8 years).
Therefore, Java developers nowadays are much more likely to be able to use new language features. It’s perhaps easy to forget which features are available with each Java version and therefore remain stuck at Java 8 features as the lowest common denominator of Java development.