I see they have gotten support for S3 (and other storage providers) via OpenDal. Might need to revisit rustic for my backup needs then! I once started looking at what it would take to build a GUI using Tauri (Rust backend <-> JS/Web frontend), but didn't have time to figure out the APIs.

What I really like about Rustic is that it understands .gitignore natively so you can backup your entire workspace without dragging a lot of dependencies, compiled binaries, and other unnecessary data with you into your backups.