Sure they do. They don't know about WP or static site, but they do know about "how long does the page take to load" and does the page work properly. It's certainly possible to build a WP set up that is super fast (and basically a SSG), but the vast, vast majority of them will not be done like that. They'll be loaded with a bunch of marketing plugins that kill performance and routinely throw errors that manifest to the user as some broken button or form that won't submit properly.
It's possible, but much harder, to build a static site that performs as poorly.
The GP doesn't have a point to miss.