Just curious, you are going to host your database on k8s? Or is there some other solution you are looking at?
My understanding is that k8s is great when you need stateless services, but gets more complicated when you need to maintain state. Been a while since I looked at it, though.
We also have a job that runs nightly to make a dump of the db and store it in the object store and the persistent disk has a snapshot scheduled for every two hours and in both cases, we are backing up the binary logs, so we can do point in time recovery much like AWS's Aurora offering.
We may eventually switch to a mariadb Galera cluster where there are 3+ master pods that distribute the load and can stay available if one pod dies. But I haven't done the research on stability of that setup yet. A few years ago it wasn't ready yet, but I imagine it is by now.