You can, but you can't deploy them. If you really want to keep your services separate, you need a separate JVM installation and jars for each service. Go gives you this automatically with a simple binary. Go's standard library is an order of magnitude (at least) better than Java's, much more comprehensive, much more cohesive, and much more capable.
Don't you think it'd be the other way around - the older a language gets, the standard libraries degrade since you can't introduce newer patterns without breaking compatibility.
I think Java is ok. I just don't like all the weight you inherit with the ecosystem. There's a lot of buttons you have to learn and history. It's working a submarine vs purposed craft (bad example).