This is a pretty dumb/blunt justification, but there is _some_ truth to it: The number of bugs in a program correlates roughly to the number of lines in that program, irrespective of language. Ergo, if some language lets you accomplish your goal in 30% fewer lines, you will have 30% fewer bugs.

The huge caveats are at a minimum that you're writing the code idiomatically (ie not putting your entire program on a single line), that it also strongly depends on developer proficiency with the language (likely lower for a newer language like nim), whether the problem you're solving is well understood, etc