JVM apparently has the disadvantage that nobody under the age of 40 wants to touch it anymore. I admit I haven't worked in it in 20 years, but I do think it's a marvel of engineering and unfairly maligned. It used to be my career but I wanted to be closer to the metal.
Having Oracle's tramp-stamp on it may have been the final kiss of death in terms of totally-superficial "coolness" factor.
and you could say the same if not better from C#. But those are now becoming niche languages and ecosystems. One for people around microsoft, azure, etc. The other around oracle solutions. There are still pretty interesting projects around it any of them, but they seem to be losing mindshare against other languages.
The JVM has a fixed size heap which for me it is wasteful.
IMHO, Microsoft made the correct approach on .NET.
For LLMs, I prefer C# and C++ instead of TypeScript, JavaScript or Python as the static + compiled language factor keeps the coding agents on track. Plus, they have a true threading/async implementation.