Garbage collector alone can't do what happens in Go language+runtime. Simplest example is that there is no way to allocate fixed arrays with non-pointer structs in Java. That is just not possible in the language.
Design of Go allows programmer to rewrite their program to make it as GC efficient as needed. You can even have essentially zero GC overhead and do stuff manually for really high performance needs. And you can also write regular code when GC isn't a big deal.
Those options simply don't exist in Java language. Your only bet in Java would be to embed some C code which is a nightmare of its own.
There is a reason why almost all backened systems that run on JVM are a huge pain in the ass even at moderate scale. They all end up rewriting parts in other languages and at the end just rewriting the whole thing.
Design of Go allows programmer to rewrite their program to make it as GC efficient as needed. You can even have essentially zero GC overhead and do stuff manually for really high performance needs. And you can also write regular code when GC isn't a big deal.
Those options simply don't exist in Java language. Your only bet in Java would be to embed some C code which is a nightmare of its own.
There is a reason why almost all backened systems that run on JVM are a huge pain in the ass even at moderate scale. They all end up rewriting parts in other languages and at the end just rewriting the whole thing.