JVM is fast for certain use cases but not for all use cases. It loads slowly, takes a while to warm up, generally needs a lot of memory and the runtime is large and idiosyncratic. You don't see lots of shared libraries, terminal applications or embedded programs written in Java, even though they are all technically possible.

The JVM has been extremely fast for a long long time now. Even Javascript is really fast, and if you really need performance there’s also others in the same performance class like C#, Rust, Go.

Hot take, but: Performance hasn’t been a major factor in choosing C or C++ for almost two decades now.