Replication is not the best way to avoid data loss. And it's not the only way to avoid downtime (e.g., the AWS Aurora PostgreSQL servers I run don't use the normal pg replication).

And there are a lot of systems for which downtime really is acceptable, at least for the amount of time it takes to restore a backup. Not everything is a front-end, mission critical system. I manage plenty of systems that are only used in a back-end batch context.

So I think it's crazy to suggest that how well a db engine's replication work outweighs all other factors. Depending on your situation it may well be the most important thing, but there's a lot of room for others to have well-architected systems that have different priorities.