Ruby is absolutely worth learning. It's a nice combination of OO and functional programming, and I find it nice to both read and write. It's very expressive; I find it easier to model my ideas in Ruby than many other languages.
The job market seems healthy and stable, but I'm not a reliable source on that.
Outside of web development, Ruby is an excellent scripting language, that's perhaps where it excels best.
Agreed, Ruby the language is fantastic for ease of use starting, then more complex concepts ready to go (functional programming, WASM, C interopt, etc) when you're ready to dive into them.
IMO the jury is still out on its recent changes to make things faster and statically typed. With so many other options in the script-language space (Python and Javascript being biggest by market share) it's difficult to grab a bigger piece of the pie, even if the newer features would be 100% perfect with no downsides.
As far as jobs, most will be tied to Ruby on Rails - the Rails framework of course being built on top of Ruby the language. And I'll mention Rails is also worth at least trying out, to see for yourself what it does and how it works.
The job market seems healthy and stable, but I'm not a reliable source on that.
Outside of web development, Ruby is an excellent scripting language, that's perhaps where it excels best.