I have been writing back ends in Java and C# for more than a decade and it is widespread for people to take advantage of multi-core systems in two ways if they can: (1) threads sharing data structures such as system configuration and caches (e.g. it is no problem to have 10 or 100 megabytes of configuration data for a Java-based system) and (2) using Executors to split up tasks into smaller pieces and running them concurrently.
In Node.js, Python, and other GIL languages you can't do the above and slow down from "configuration at the speed of RAM" to "parsing configuration over and over again", "configuration at the speed of the database", etc.
I see people using Node.js for build systems but I think it's still an unusual choice (like Python) for a back end for a commercial system.
In regards to Node, as Python is anyway mostly CPython 99% of the deployments.
It would kind of seem like a wash to me, naively.
Let alone the detail that the goroutine is full blown native code, while the node/Python process is interpreted, and even if a JIT is used, many C2 level optimisations are out of reach for dynamic languages.
It is no wonder that even with the herculean effort that has gone into V8, for the ultimate performance it needs help from GPU shaders and WebAssembly, both typed.
The perf difference here probably isn't that great (although Java/Go will likely still be faster), but if you're at the point of running multiple processes you may well find that it's less dev effort to write your code in Java/Go (assuming you are familiar with both).