I wouldn't say plain, but it's a generic LLM design. Which made me curious whether the blog was around with a different look before AI was commonly used for such things, and it turns out it was, at https://www.pzuraq.com (which now redirects to the current site).
One article survived the move, so you can compare:
One article survived the move, so you can compare:
https://web.archive.org/web/20220426154343/https://www.pzura...
https://maevyn.codes/four-eras-of-javascript-frameworks
Edit: Loading any page of the old blog on archive.org always errors out initially. Click back to the blog list and then on the article again.