Resharding in vitess is not quite as magical as this post implies. My infrastructure team has tried resharding the cluster powering my app several times and each time it's failed.

It's been a while since the last attempt so I forget the details but I think the reshard replication lag was growing no matter what resources we threw at it. We've since scaled vertically instead and are working on architecture changes to reduce our MySQL load (which admittedly is extremely high).