Are faculty positions more competitive than government research lab positions?
Of course the answer depends on the university and the lab.  There are plenty of university departments with low standards, and some labs are truly excellent.  However, I think your comparison is right on average for top universities vs. national labs in the U.S.  There are several reasons for this:


Many researchers at universities aren't professors, and in some universities the non-faculty research staff outnumber the faculty by a substantial factor.  To make a fair comparison, you should not restrict your attention to professors, but rather compare all research staff in both institutions (or look at especially noteworthy or high-level employees at labs).
Some research labs are huge.  For example, Los Alamos and Sandia are each the size of a whole university, but they cover a much narrower range of fields.  The top researchers at these labs are exceptional, but the sheer number of positions makes it difficult to maintain the highest standards for everyone.  (And you can't just keep positions open for years while you look for the perfect candidate, since that would compromise the lab's mission.)
Researchers at national labs in the U.S. do not have tenure, and their jobs are subject to availability of funding and political interference.  In some cases they face as much or more pressure to get grants as faculty do.