The Ahead of Time compilation is pretty nice for some stuff. Generally startup time is significantly improved, so if you're writing command line tools in particular it can be cool.

Most languages I write are ahead of time compiled with pretty good startup time so it's not really a need I have that I feel GraalVM solves?

Yes but Java has historically had pretty long startup times. If you want to write Java specifically then GraalVM is probably still the best option for AOT.

OpenJDK is from Oracle as well.