In addition to the above, I also have some more subjective comments to add.
Shared memory parallelism is risky, and very hard to get right. Non deterministic bugs in the VM are no fun at all for Python developers.
It took the developers of the HotSpot JVM many years and many many person years to iron out all the concurrency bugs. I don’t see any reason to believe that we will do any better.
If you want robust parallel, scalable applications, you write them in Erlang, not Java.
If you need the very last drop of performance you might use Java, although you would probably use Rust these days.
It is safe to say that if you are choosing to develop in Python, you aren’t worried about getting the last drop of performance. You might be concerned about robustness and reliability, though.
The share-nothing model of multiple interpreters has its usability limitations (you have to pass messages) but it is much safer IMO.