JSON data within a database is perfectly fine and has completely justified use cases. JSON is just a way to structure data. If it’s bespoke data or something that doesn’t need to be structured in a table, a JSON string can keep all that organized.
We use it for intake questionnaire data. It’s something that needs to be on file for record purposes, but it doesn’t need to be queried aside from simply being loaded with the rest of the record.
Edit: and just to add, even MS SQL/Azure SQL has the ability to both query and even index within a JSON object. Of course Postgres’ JSONB data type is far better suited for that.