I don’t see how it’s an improvement over C# structs. C# structs are value types so they are copied when assigned to a variable like primitives. There is no ambiguity because it’s a struct.

To avoid copying you have to explicitly declare a ref variable/parameter.

You can get the same immutability as value classes by using ‘readonly struct’s or ‘readonly record struct’s.

Java value classes are stranger because they are heap allocated by default and are only flattened/scalarized/stack-allocated when certain conditions are met. It’s the same as a class, but with extra restrictions, so that the JVM can possibly optimize memory layout at runtime.

C# has Properties that make setters look like fields anyway. There's no ambiguity between value and object in C# because there is no promise that that syntax only sets a field. Love it or hate it, you just need to know what you're calling.