Ask HN: Anyone use HTTP/2 server push?

I've been looking into HTTP/2 server push recently* and I haven't found any sites using it, including the big tech firms. So I suspect that it isn't really useful in practice. Does anyone here use it, or know more about its adoption?

* As I was hoping to add more context to https://medium.com/python-pandemonium/how-to-serve-http-2-using-python-5e5bbd1e7ff1.