I’d argue they risk losing users who post links to their videos online. It’s likely the same group who tend to use ad blockers are also the ones more likely to link a video online, so YouTube would miss out on all the non-adblock users clicking links and watching the videos that way.
Would’ve liked to see what percentage have none.
I’m still buying CDs to rip and having my music library as MP3s on my phone. No internet connection required, I have total control of the files, and a physical backup if needed.