Pretty astute analysis. There are things people will pay for of course. Not for content available on youtube, and paywalls will turn people off, as you rightly point out. People more or less have time to browse and we consider it non-spending lazy time, free entertainment time, and paywalls bounce us away to other content.
However wouldn’t you pay to have your favourite creator read and respond to your message? I’d pay £2 for that. this could be trialed on a funding website, video responses could be on twitch, or combining a funding website with a youtube live stream/ recorded video, or even just on a text response via facebook (longer replies).
Having a free reply session, then a paid for reply session could be a great way to encourage paid support via community interaction.
As for paid content, I think this will only work with a wallet system (not always reaching for the card) where each video is like 10p to watch. so small, people are happy to click. This way it is like paid subscription tv, but you vote what you like with 10p clicks.
consider this suggestion free.