@pixelambacht (late response, but in case it still interests you:)
For many years now, I've been using text-only news servers, so I don't see binaries (but maybe some servers filter these differently?). Spam got worse in the second half of 2023 but Google was to blame for that and they disconnected Groups from USENET a couple weeks ago.
And yes, some people are still using it, although it will of course depend on the group. An example: alt.folklore.computers is active :-)