What balance? As explained in the article, the Markermeer was basically dead. This project has given the lake a chance to get some balance in the first place.
And some more precision: this is about the uppercase Eszett. The lowercase variant has existed for ages, and before 2017 was officially uppercased into SS or SZ.
Your remark about isolation is not entirely true: when you run multiple services in one VM, there are still a number of shared resources.
Most notably, all services will share the same heap, so one ill-behaved service can bring down all the other services. The only way to prevent this, is to run each service in a separate VM.
And at that point, you are once again comparing one Go runtime per service with one JVM per service.