There are many ways to get Elastic wrong, index templates and field types, shard sizes, number of primary and replica shards, node heap size, and those are only a fraction. It's very easy to get Loki right in comparison.
Elasticsearch being strongly typed I think creates a lot of overhead since you need to manage the schema for all your logs. Loki only expects certain (indexes) fields which are key, value pairs so you can throw all kinds of data into it and only mess with schema when you're querying