I've used it in a personal React note-taking app project, to add basic offline functionality.

It's a nice idea, and it's pretty magical to be able to build an interactive website that can work fully offline. That said, there are some pitfalls you have to watch out for, e.g. database connection contention if you have multiple tabs to the same origin open.

The lack of great tooling around indexeddb is also a bummer. Something like TablePlus but for indexeddb would be great.