It is, but if all you want is a JVM, Java is still probably the worse choice over Scala or Kotlin

The exact opposite is true. Scala's and Kotlin's syntactic sugar comes with tonnes of overhead and additional allocation. Java is pretty raw compared to them and allows you to stay closer to the C-spirit and thus retain more control over the side effects of the code you write.

You can write Scala to pretty much just look and run like old school Java if you want.

I haven't seen any benchmarks, but I doubt a Scala app written idiomatic style would be any slower than the Java version written in idiomatic style.

Also, what is this C spirit we are trying to stay close to? I'm certainly not interested in any "C spirit"

The C spirit I'm referring to is the raw, verbose and low-level-ish nature of writing code in C. For high-performance/low-latency Java apps it is absolutely crucial to have this level of control over code and resulting instructions emitted by the compiler. On the other hand - if you don't care about it and want to focus on domain-level stuff you absolutely can. This is what I find the most appealing about Java.

Yeah, absolutely. It's objectively worse than most languages.