Not the OP, but you raise good points. Performance might also be a concern, thinking of languages like Python and its ast package (not sure that’s accessible without going through the interpreter).

For a tool I’m writing, the tree-sitter query language is a core piece of the puzzle as well. Once you only have JSON of the concrete syntax trees, you’re back to implementing a query language yourself. Not that OP needs it, but ast-grep might?

Yes, ast-grep already has its own rule syntax [1]. But still parser performance and binary size are critical factors for a general tool.

https://ast-grep.github.io/guide/rule-config.html