If it fits on a single machine - jq, flat files, JSON lines / avro if relatively flat. Change to a tabular format if when nesting not required.
Postgres JSONB works, but it requires maintaining a heavy server process. So does Lucene/elasticsearch.
I have been yearning for embeddable store (in line with SQLite the support that both works and also keeps the data compressed like JSONB). I know there were some attempts, tried some of it those, mostly monstrosities).