But there are Rails-like frameworks you can use in Crystal that are just as much fun (though understandably less mature).
Check out Amber, Lucky, and Kemal to give you an idea of what’s out there.
Disclaimer: I haven't used it, just read a bit about it.
The same, if not more so, goes for Go. It might be statically compiled, but it's far from the most optimised performer.
What other languages? Because the language uses "Fast as C" as part of it's tagline. Is this a false claim?
I've personally found that a lot of Go's marketing is, if not misleading, outright false. As an example: https://blog.plan99.net/modern-garbage-collection-911ef4f8bd...
Beware trading a visible cost for an unbounded number of smaller costs. In Go's case, in return for minimal pausing you get memory fragmentation, terrible performance if the GC is ever seriously taxed, and a 100% (!) heap memory use overhead. If you're just writing commandline daemons or servers you restart every ten minutes though, who cares?
Go doesn't come off too badly in this because it's not Java, which allocates like crazy. That's a laudable tradeoff, but that does not mean they solved garbage collection very well.
All they want is ruby with static types, that runs fast. Those things will satisfy them alone.
Intelligently written C/C++/D/Zig/Rust will always knock Crystal out of the park. :(
Go - I want to program explicitly and don't mind a little extra code or syntax to do it. I want close to the best performance possible and a single distributable binary. I don't mind being encouraged to "roll my own" api / web app rather than using a framework.
Crystal - I want to feel like I'm writing in Ruby, but with type checking at compile time and much better performance. I don't mind being a little less performant than other compiled languages. I want access to Rails/Sinatra-like frameworks for web/API apps rather than having to "roll my own".
Basically, if you want something quick and fun that can run in production, I love Crystal. If you want something that needs to be custom and highly performant, I love Go.