Having interacted with Elasticsearch a lot, I assure you there is a lot for them yet to improve. Frankly, I think Elasticsearch followed the MongoDB model of "make it easy for developers to adopt and then make it good." MDB did that by making it easy to throw "schema-less" documents into their database and then later working on "advanced" things like avoiding data loss [0]. Elasticsearch did something similar in that you don't have to run a separate cluster coordination server like Zookeeper which Solr requires. It's also easy to get up and running with indexing unstructured data. Running it at scale with heavy workloads? There are still plenty of rough edges there. It's a good way to gain market share and both products have definitely improved, but I wouldn't want my day job to involve the operation of a large Elasticsearch cluster.
[0] https://pastebin.com/raw/FD3xe6Jt