In my humble opinion, it would benefit all better if we standardized something like jql (jira query language, so the user layer) first. From experience, many who find sql too complex have no problem with writing complicated jql queries. it's both easy to use and a great first step to writing actual SQL. I wish it was a standard like json.
The way the JSON filters work would be directly coupled to the JSON fix notation and SQL infix notation so it's directly coupled to SQL and doesn't really require a standard, imho.