https://www.rethinkdb.com/docs/sql-to-reql/javascript/
Frankly, I cannot understand to write queries that verbose and complex when SQL looks clear and concise.
If I'm missing on how good RethinkDB is, I will gladly like to know.
One part SQL is notorious for is you don't know where it could fail until you send the whole query and receive the error unlike these NoSQL where operations can happen progressively.
While ORM can sort of mimic that behavior, I don't like that it hides SQL which makes crappy SQL alot easier to write and harder to debug.
There are niches though. Graph databases, search indexes, databases for logging, time series databases, mapreduce, etc.
hell, you can even use your favorite (postgresql) rdbms to queue tasks