On the other hand, my main frustration with WP (and Jekyll for that matter) is that 99% of my older posts will never change, so why display them dynamically? They should be built into HTML, cached, and forgotten.

That's the most logical "complaint" I've heard about WordPress. I wish it could do that as well. But ... I know that I often go back and fix older post (spell and grammar check, image size too small, broken links, etc.).

There are plugins that allow the operator to generate static pages from WordPress posts. WordPress then just becomes a front end to a static site generator. However, then you wouldn't be able to leave a comment.

I have tried Grav, a flat file CMS that produces static site content. It has a usable front-end web UI for creating and managing posts and images. If I remember correctly, post are saved as Markdown text with Front Matter; similar to Jekyll and Hugo.

I used it in test mode for a bit but did not find an easy way to port my existing post and images. I spent a week correcting mistakes in the importer. After correcting about 50 posts, I gave up. Maybe I should have stuck with it.

I would gladly use Jekyll if:

• The site rebuild problem was solved without hacks
• I could use a Web UI on my own server to create/edit/manage posts and images. Jekyll content creation isn’t mobile friendly.
• There was an open source comment system I could easily integrate on my own server. I don’t trust Disqus.

I don't do any caching yet. I have am old Cloud Flare account that I may dust off to see what caching can provide.