Static website generators fill a useful niche between handcoding all your HTML and running a server. However there's a plethora of site generators and it's hard to choose between them. However I've got a simple recommendation: if you're writing a blog use Jekyll (if you don't want to use something like Wordpress).
This site is currently using Hugo through a Github Action. I've also used it to publish Jupyter notebooks and R Blogdown posts. However Hugo makes breaking changes, which forced me to change my theme and doesn't have an easy way to render diagrams.
It would be great to be able to put declarative diagrams inline with the article. Unfortunately it looks very unlikely Hugo will support PlantUML; someone would have to port it to Go. I ended up resorting to using Mermaid for diagrams but client side rendering makes it much slower to load and paint the page (it's a major factor according to Google site tools). This makes it a less pleasant experience and hurts SEO. Jekyll will be much slower to generate the website than Hugo, but with something like the Jekyll PlantUML it could generate a website that's much faster to load. Another way to do this would be with Blogdown, which renders the pages using RMarkdown which executes code in R then uses Pandoc to convert the output, and hands off to Hugo (or other generators) to make related assets from the HTML output.
I'm not sure if it's worth me switching to Jekyll now with it's wide array of plugins and themes. I'll have to investigate the tradeoffs more, and compare it to filling the gaps with RMarkdown. But I regret picking Hugo over the more stable, popular and featureful Jekyll. I'm not the only person who has had issues with Hugo, as can be seen on this Hacker news thread.