I could count the number of startups I’m aware of building on Java on one hand, after a wood chipper accident. For perf it’s rust, for web it’s Go or node/deno/bun for single front/back language.
Remember that "Systems Programming", which is what Golang was designed for, isn't necessarily just Kernel and device drivers, but everything that isn't "Application Programming", and that includes the whole K8S networking and container stuff where it is very successful.
And when it comes to concurrency Rust is the worst language I've ever used by far. The type checker makes dealing with objects between threads extremely painful. With the JVM it's all just handed for you.
Rust is great when you want a tiny binary with minimal memory consumption.
Looking at TIOBE and PYPL, it comes that for backend Java and .NET are huge, followed by .Node.js, followed by Python and then PHP.