One thing I don't get is why not have an on prem solution with cloud fallback? It's hard but not super hard. You would just need a cloud data store. And dependi

One thing I don't get is why not have an on prem solution with cloud fallback? It's hard but not super hard. You would just need a cloud data store. And depending on your app, you can have on prem data store that periodically backs up (and no egress under normal operation) if you can design with an eventual consistency models.