Shouldn't be built with Node.js? Nothing. Node.js is good for everything. It's by nature not performant in certain use cases or complicated to use in particular environments. By avoiding certain types of apps to be built, we can't go forward. We shall alway try to push back all kinds of borders. That applies to all languages and environments.
What wouldn't I build right now? File-based processing like video encoding. But only because I am inexperienced with certain video container formats, SIMD.js and Node.js cluster.