You need a larger team to do automatic failover because getting it right is a massive PITA. Either that or pay someone to do it right for you, e.g. RDS, managed

You need a larger team to do automatic failover because getting it right is a massive PITA. Either that or pay someone to do it right for you, e.g. RDS, managed solutions. Manual failover is often a lot safer, automatic systems have a nasty habit of not doing what you expect them to and trashing your database / losing data.