barring competition languages seem to stall out over time. Java fell out of favor because every java app turned into a pile of xml and factories that everyone hated and was slow to develop. The faster evolution of peer languages allowed for recognition of what people didn't like in Java (The ceremony of getting setup and invoking "app" logic).

The better parts of Scala, kotlin, and the guava library are steadily making their way into the language. But if there wasn't competition the language would absolutely stagnate again as risk aversion sets in.