Many sites are Read (almost) Only. For sites where users interactively query/view/explore the data, but (almost) never write their own, it works great.
If you chuck Varnish in front of it, does it matter what you use?
Edit: was being serious: if your data is that static you can statically generate it. But I get that CMS is convenient so with that caching is where you get the performance win. A blog post either never updates or gets 1 or 2 edits max.