I've recently switched my blog from WriteFreely to a custom-built solution: MD-Blog (MD, of course, stands for Markdown). The trigger was a failed update of the old system – but in the end, it was the perfect incentive to radically simplify everything and gain full control over the design.
The core consists of simple Markdown files in the data/ folder, which are converted into modern HTML at runtime. The result is lightning fast, works without a database, and thanks to a custom design system (including dark mode), it now looks exactly as I imagined. Even a modern Mastodon share button is now directly on board.
If you're interested in the code or the lean setup, feel free to reach out to me via Mastodon!