I’m not sure if you’re familiar with what Rails really is. It doesn’t have an admin panel.
Node is a language that you could compare to Ruby.
You can ostensibly do the exact same thing with Node that you could do with Ruby on Rails... but you’d be reinventing the wheel all over the place and duct taping lots of different modules together that all utilize different design patterns.
If you’re good at designing systems, you can do it just fine, albeit slower than I could with Rails. But it’s possible. I have nothing against Node but there’s a time and a place for all tools. Getting an MVP up is not one of them, imho.
Node.js is missing a great ORM but other than that I don't see many things missing in Node.js anymore.
There is also Rails' admin panel but most projects don't need that.