What is always astounding to me is that people talk as if caching isn't a thing. It could hardly be easier to cache the html output from wordpress at either the webserver or CDN level, and it will perform just the same as any "static site" (of course, images, css etc will dictate how it performs once the browser receives the cached html)
> people talk as if caching isn't a thing
Maybe you'd be surprised by how little some "engineers" know about http cache headers.
Caching is rarely that simple though.
With a static site you know the output can be cached indefinitely and only invalidated by a new deploy.
With a server rendered site you can only recreate that by tracking ever piece of data a page is dependent on, tracking data changes, and invalidating any page a data change breaks.
No one does that though, so you may go for SWR or a short-ish cache window so changes take some set of minutes to roll out, looking like the delay in waiting for a static site to rebuild.
I'd never pick between static and server rendered based on caching. Factors like the size of the site, frequency of content updates, and technical skill of content authors (I've never found a git-based CMS I'd ask someone totally nontechnical to use).