That’s an absolutely bad take. Java is still very very conservative with every change, and they almost always have only local behaviors, so not knowing them still gives you complete understanding of a program.
Like, records are a very easy concept, fixing the similar feature in, say, c# where they are mutable. Sealed classes/interfaces are a natural extension over the already existing final logic. It just puts a middle option between none and all (other class) being able to inherit from a superclass.
C# records default to immutability. However, struct records being a lower level construct default to mutable (which can be changed with readonly keyword):
record User(string Name, DateOnly DoB); // immutable
record struct Cursor(int X, int Y); // mutable
readonly record struct Point(int X, int Y); // immutable
Like, records are a very easy concept, fixing the similar feature in, say, c# where they are mutable. Sealed classes/interfaces are a natural extension over the already existing final logic. It just puts a middle option between none and all (other class) being able to inherit from a superclass.