This is neat but I'm not really seeing anything I can't do with standard SQL and CLI tools like psql. Seems like you'd learn more reusable things using standard SQL too.
If you use things like `array_to_json(array_agg(row_to_json(....)))` in your psql commands to output some rows to JSON, then sq's `--json` or `--jsonl` is quite a bit easier IMHO. If you know the exact SQL query you want to run you can just do `sq sql '....'` as well, but I agree there's not much point in doing that if you aren't taking advantage of some other sq feature.
Developer here. There's a few features other than the query stuff that I still think are pretty handy.
The "sq inspect" stuff isn't easy to do with the standard CLI tools, or at least wasn't when I started working on sq back in 2013 or so.
I also regularly make use of the ability to diff the metadata/schema of different DB instances (e.g. "sq diff @pg_prod @pg_qa").