Except for in-the-box replication and failover options.

"in-the-box" unless you're using the "cheaper" licence options. (possibly out of date opinion)

MSSQL's replication is a minefield of ways to screw it up completely.

Not that I disagree... but by comparison, PosgreSQL replication would be a minefield of nuclear bombs without a map.

Not using it for anything super critical yet, but Patroni is pretty much plug-and-play, and becomes transparent to the client once set up. No need to worry about whether your client supports MultiSubnetFailover, or whether you remembered to copy your users manually.