I moved from static HTML to 11ty (https://11ty.dev) for the same reason and I'm pretty happy with how simple it allows you to keep things. Plus, it helps me avoid yak shaving instead of writing content!
I think for a site like this I'd go with 11ty, just a clean project without a template or custom config, one collection to pull the photos from Flickr inline the styles.
(just sharing my personal approach, nothing wrong with Jamie's approach, ofc)