I make no claims as to the presence of malware (or lack thereof) in the links in this comment, and I'm not condoning or endorsing anything, nor am I stating an opinion on the ethics of downloading YouTube videos for any purpose, but for the sake of adding information to the table, there are still options available:

https://newpipe.en.softonic.com/android/download?utm_source=...

and,

https://yt3-music-downloader.en.softonic.com/android https://f-droid.org/en/packages/org.schabi.newpipe/

and: https://addons.mozilla.org/en-US/firefox/addon/easy-youtube-...

And I'm sure many others. I guess as long as the situation is such that it is not stupidly easy to figure out how to get around the restrictions that "prevent" downloading YT videos, workarounds and options will continue to be available. Information is very hard to lock away if it is on the internet and available to the public to some degree. I imagine he situation is considerably different in more totalitarian countries like China and North Korea, where content and online activity is scrutinized/monitored by the government more "thoroughly".

It seems hard to find a line in the sense that recording technology is becoming more and more common, as is the trend of social media companies wanting the masses to "share" their experiences on social media. Hypothetically, if I record a concert with Snapchat spectacles and then upload the snap to YouTube, am I committing some kind of copyright infringement or am I simply sharing an experience with my "followers"? I have actually had videos of concerts that I recorded on my phone taken down from YouTube, even though it wasn't like I recorded with a professional camera or even that the recording sounded particularly good, but I guess some content management stoolies on YouTube (and I imagine Vimeo and maybe LBRY/Odysee/elsewhere) are paid to try to take down content that appears to be bypassing the creators' ability to collect money for their material.