Author of the post here, couldn't agree more that if you don't have to shard then don't. Scaling out using replicas is an option to certain scale, you do have to ensure no long running queries and make sure your replication is up to date. Those are another option of things to manage, and at an intermediate stage very viable ones, at certain scale it all changes a bit. All that said if you're at a small data level I wouldn't encourage sharding for the sake of it.. if you know you're going to have to scale beyond a single node or approaching limits where you're frequently scaling up it's good to know your options and plan ahead.