MySQL Read-only Replication
It depends on the version.
Look for &quot;multi-source&quot; replication.  This is where multiple Primaries can replicate to a single Replica.  But this does not say how you would restore a single Primary that dies.
Consider using a single Primary for everything, then have one (or more) Replicas.
Or you could have multiple Primary-Replica pairs sitting in VMs or Dockers.  The pair would, of course, have its parts on separate machines, preferably geographically separated (think storms, earthquakes, etc).