[delusional]

Java didn't really "sit it out". It launched CompletableFutures, CompletionStages, Sources and Sinks, arguably even streams. All of those are standard library forms of async programming. People tried to make it catch on, but the experience of using it, The runtime wrapping all your errors in completion exceptions, destroying your callstacks, just made it completely useless.

[jen20]

Every Java codebase using something like Flux serves as a datapoint in favor of this argument - they're an abomination to read, reason about or (heaven help) debug.