In deep learning a lot of papers end up only on arXiv, and authors don't bother (or need) to send it anywhere. Or even more, some seminal papers and up only on the author's page (e.g. one introducing GPT-2 https://openai.com/blog/better-language-models/). I am not a big fan of the latter, as it gives problems with long-term availability.

Moreover, the correlation with acceptance and impact in existing, but not that high: https://medium.com/ai2-blog/what-open-data-tells-us-about-re...

Of course, only corporate researchers can rely on not publishing in established journals - as their salary and position does not come from "publish or perish" metrics. Ironically, it means that there is more academic freedom in private companies than in academia.