I run a few WordPress sites, two very small, one pretty large, and I've got to say WordPress and the maturity there is truly incredible. I used the Simply Static plugin on one of the sites and it is great. The other sites are way too dynamic however. I can't even use much caching because of that, so performance is a constant battle.

The big site is getting ported to Elixir/Phoenix in the next year or so, but it will be tough to match feature parity for the content producer(s), who are very non-technical in nature.