I run an offline-first app[0] that has a sync mechanism (over Yjs). To solve server longevity we just sell you a lifetime license of the app and allow for file-based sync. While I agree with the sentiment of the article most users do not even know what a server is, much less capable of self-hosting. Syncing a folder over Dropbox or Google Drive, though, is simple enough. [0]: https://nestful.app
For your app, how do notifications of changes get propagated? Does it depend on the backend (Google Drive, etc) supporting that, or does it just do polling or something?