I think the comparison would be kind of unfair, since Go Fiber is a web framework that is inspired by Express. So from a syntax point of view they are very similar (e.g. that `app.use(XYZ)`). Just citing the Go Fiber official readme here:
"Fiber is an Express inspired web framework built on top of Fasthttp, the fastest HTTP engine for Go. "
So what you could do is compare the programming language Go with JavaScript, if you want. But comparing Go Fiber with Express doesn't make a lot of sense IMO.
I think you just saw mostly Express examples since you JavaScript has a way bigger community than the Go programming language ;-)