Nodejs = you can build apis
GO = you can build apis but they're faster
Rust = new C++ and really fast
it seems to be best supplementary language combo to learn would be
Go/Rust or Nodejs/Rust
this way you know one good web/api language and one really efficient language.
Having said that, it depends on what you want to build.
In my opinion, Go is great for building command line applications, infrastructure applications (Kubernetes and related stuff), your own database, a DNS server, or anything you would otherwise use C/C++/Java? etc.
If the answer to the question: What would I write this in if Go didn't exist? is C/C++, etc... then Go is what you're looking for. If the answer is Python, Ruby, php, etc... then node is a better fit (compared to Go).
For building Web Applications, and web realted APIs, again in my opinion, what you need to focus on is in the ecosystem, not the language. You need to focus on the libraries, the frameworks, the tooling, the editors, the ORMs, the validation libraries, etc, etc.
In this regard, I think the node ecosystem is a lot more suitable. You might need to do scraping of other websites, generate PDFs, access a database, render a preview from an url to an image, etc. Node has an infinite amount of useful and popular libraries for all web stuff.
At my previous job everything in the backend was being rewritten in Go. The inseane amount of reinventing the wheel and wasting time on things already given for free in other ecosystem was astounding. To me an extreme example of this was the "We dOnT NeEd OrMs iN gO" and then see the team suffering weeks to do the right migration statements in SQL files executed by custom bash scripts and creating manual CRUD queries for trivial data which, with the Rails ORM, the Django ORM or Prisma.js would be literally 30m of work, migrations and deployment included.
But hey, Go is so fast! So go ahead with Go if you're already FAANG scale.