Django Ninja just hit 1.0 a few weeks ago. I think you are going to have to be patient to find large sites using it in production.
Is it a "1.0 because we think it's done and you should try using it now. Maybe it'll work." Or "This is a solid 1.0 that has been tested in production. You can expect reasonable api stability."
FastAPI launched with option three: "We're going to get our friends to use it in production so we can say it's deployed by Microsoft, but, this is definitely a pre-alpha."
It is so easy to set up and use and it's at worth giving it a spin if you're curious.