I disagree with this. The tooling around JVM is great or at least good enough.

Maven is mostly smooth sailing comparing to Python's env solutions or JS ecosystem. Maven is 21 years old. A quick search says Python has/had; pip, venv, pip-tools, Pipenv, Poetry, PDM, pyenv, pipx, uv, Conda, Mamba, Pixi.

Debugging is just fine. Modern debugging tools are there. There is remote debugging, (although limited) update & continue, evaluating custom expressions etc. I don't know what they complain about. If using Clojure, it is also possible to change running application completely.

Monitoring tools are also great. It is easy to gather runtime metrics for profiling or monitoring events. There are tools like Mission Control to analyse them.