True, I have to maintain state on S3, but there's not much work involved in that.
If I was maintaining my own database server, I have to manage upgrades, backups, and the complexity of running an additional server. With Litestream, I don't have to manage upgrades because nothing bad happens if I don't upgrade, whereas there are security risks running an unpatched MySQL/Postgres server in production. Litestream has built-in snapshots and can replicate to multiple S3 backends, so I'm not too worried about backups. And there's no server to maintain.
What operational complexity do you see in Litestream?