I'm not sure I understand your second point. Yes, if the external replication target is unavailable, I can't bring my local service back online. Same goes for if the replication target becomes unavailable and I don't realize it, there is potential for a lot of data to be lost if the application restarts.

For my personal usecase this is fine. I also have monitoring setup to look for just this case. It's a tradeoff between resilience and simplicity that works for some use cases - mine included.