[tapirl]

> Go is at the complete opposite end of the spectrum - not flexible at all,

You must be kidding. Go is the flexible one (not one of) in static popular languages. It is even more flexible than many dynamic languages. It supports function types as first-class citizen, closures, value methods as functions, type methods as functions, type deduction, .... IMHO, the main sell point of Go is not simplicity, but overall balance and flexibility: https://github.com/go101/go101/wiki/The-main-sell-point-of-G...

> there’s very poor functional programming support,

This is true currently, but this is not caused by lack of flexibility, it is caused by lack of custom generics instead.

[yashap]

Fair enough, flexible is an extremely loose term. I was referring mostly to the ability to a language that's flexible enough to let library/tool authors create their own very high level abstractions and DSLs. In Go, lack of custom generics often makes this very difficult. You look at the kind of APIs offered by mega-popular data science toolkits like pandas and Spark, it's really hard to offer something similar in Go. You end up with a lot of inferface{} types everywhere, vectors/series/whatever carrying their type in a struct field, etc.