Java will never be as expressive as Scala. Scala's feature set allows for writing complete DSLs as well as concise, terse code. That said, Java is getting closer. Since JDK 14, Java has had preview support for "records" which are similar to Scala's case classes. In future JDKs, records will have near feature parity with Scala's case classes.
For me, the most expressive feature of Scala is its case classes with pattern matching. Once you've coded with this feature, you'll never want to return to the alternatives. This repo shows Java's progress towards equalling Scala's case class feature. It's unlikely that Java will ever completely match Scala, but it will get close.
Shown here is a very old interpreter from the Scala examples website rewritten in Scala 3. It's not meant to be a definitive example. However, it's simple, fits on one page and shows the expressiveness of case classes.
The Java version takes advantage of records and Java's support
for pattern matching. Record patterns are now available and the
Java version is nearly identical to the Scala 2 version. Record
patterns are limited to type comparison and extraction and so
can't match on, for example, empty-list but that's about the only
feature missing. Java is still more verbose (the need for var
for example) but it's impressive how close it is now. Note that
I had to write a few static methods to eliminate the use of new.
However, Scala 3 has significantly improved by adopting the enum
syntax for sealed hierarchies and eliminating the need for most braces.
As a result, Scala is now even more visually appealing than before,
resembling Python and Haskell. While functionally, Java appears to
have matched Scala's case classes and pattern matching capabilities,
its use of braces, operators < and > for generics, and general
verbosity makes it significantly more challenging to read compared
to Scala.