Every time I try, I keep going back to .NET, which has been optimising for faster startup time.

Almost all Java benchmarks are for the "steady state" after half an hour of warm up time.

Doesn't Java have an AOT solution too? Is it not ready for prime time?

Other posters here seem to misunderstand what AOT means in today's Java. It just means caching some state. There's still a JIT involved, it's just warmer.

There are other solutions that give you MUCH faster startup with lower memory e.g.: https://foojay.io/today/java-server-work-before-startup/

Edit: it seems I missed that 28 added the actual native code compilation phase so it will probably be closer to the GraalVM numbers in the link above.