I've decided to change this site's front page to show just the latest post in full, and have a link in the sidebar to a separate archive page listing posts by month.
This turned out to be easier than I'd thought, as WordPress now has built-in blocks for handling this.
The reason for these changes is that they'll hopefully mean better coverage of changes to the site by the Internet Archive in the future. I have a plugin installed to ping the Archive on each update, and it is working well for individual posts, but the front page wasn't being captured as frequently as I'd hoped.