Technically it is. It's just a non-interactive browser.
Isn't that kind of like saying my pressure washer is a non-ambulatory car?
More like your newspaper isn't a TV. You still get the news, but it's a different format.
If we envision a spectrum ranging from an HTTP(s) client to a full-fledged web browser (like Chrome or Firefox), I would place cURL very close to the HTTP(s) client end of the scale.