> OPFS finally adding a filesystem to the browser made seem like the web file database situation could finally standardize but COOP/COEP ruins it.

We have two OPFS-based VFSes. One requires COOP/COEP and one does not. Each makes feature trade-offs, though, so they're not equivalent.

We also offer persistence via localStorage and sessionStorage, so OPFS is not (for small databases) required for persistence.