Java is not outdated tech. Your advice seems pretty solid overall but Java is definitely not outdated tech. I would expect as much from a non-coder giving advice though.
No one outside of Java developers wants to deal with it. Take your pick why, constant security problems, Oracle's shitty litigious attitude, miles of crappy java code Ops people have to deal with that was built by the lowest bidder, the fact that the JVM/virtual machine pattern that has been superseded by VMs/docker/serverless/microkernels/take your pick.
Just about the only people who greenfield in Java these days are academics who learned Java as an undergrad, Enterprise people who are stuck with java everything-else so why not, and java developers who don't know anything better. Oh, and business guys who force Java in their applications so it can be easily outsourced to India once the buyout check comes through.