Do you definitely need Apache? I thought PHP worked fine without that these days - or does Wordpress only work with something that supports .htaccess too?
I guess to the OP's point, it does still require PHP, FPM, a number of other PHP extensions, and the webserve all to be installed on the server. At which point, MySQL is just one more dependency. I would argue that SQLite is a little easier to back up and transfer than MySQL, but WordPress does that make easy anyway.
I wonder if there's a plan afoot to embed the whole thing inside an Electron app for some kind of portable TiddlyWiki like service.