That is a good example why betting on the platform languages is always a long term safer bet than betting the house on guest languages,
Eventually they won't keep up with the underlying platform.
It's not like it isn't working. Scala runs fine on JDK13 (probably 14 too, but we currently run one Play project in prod on 13).
Java is a pretty safe bet, as it has an outstanding backward compatibility track record.
Support features of JDK 11+ https://github.com/scala/scala-dev/issues/139
Support Java Module System https://github.com/scala/scala-dev/issues/529
In comparison language features seem to attract much more attention:
Removing existential types https://contributors.scala-lang.org/t/proposal-to-remove-exi...
Significant indentation syntax https://github.com/lampepfl/dotty/pull/7083