I always thought it's better to host distributed database, like Cockroachdb and Yugabytedb, in multiple kubernetes clusters. Just in case one of the cluster goes down.
A K8S cluster is already designed to be highly available and self healing. Stretching across clusters is usually a special case of scaling across datacenters/regions and brings a lot more overhead and complexity.
yeah, theres a point for anyyone where they would say "i accept that level of risk". for example, datacenter outages could be where many companies simply tap out.
Kubernetes doesn't "failover" like that. Each cluster does it's best to keep your workloads running but stretching across multi-clusters is your responsibility. There is K8S Federation [1](previously called multicluster) which is about deploying from a single host cluster to multiple other ones, but it's still unfinished, and either way K8S doesn't know much about your application itself to be able to perform any kind of failover switch.
Usually if it's a stateless app then the solution is using a global load balancer or other networking at the edge to steer traffic to the responsive regions. Databases also tend to have their own replication and distribution strategies handled internally that should be used, along with the above mentioned networking.