Would you pay to avoid ads on YouTube?
With the adblocker online, you mean?
From what I understand, YouTube has it great at the moment: they share the content freely but gather revenue from donations from Patreon or somesuch. If you want to support the content maker, you can donate as much as you'd like - or you can never give them a cent and still enjoy the great stories and great informational resources they provide.
People like CGP Grey who thrive off quality content make thousands of dollars every month by publishing one polished, interesting and informative video (he makes staggering $15 thousand off a single video which he releases once in a while, plus $2.5k+ off a single Hello Internet podcast episode). Someone like Birgirpall, whose videos are still good but in a very different venue, can make quite a bit by putting forth several shorther videos a month (Biggi and Banzaii make $766 off of a single video while releasing 3 or 4 per month). Then, if someone like Markiplier ever needed personal money through Patreon, if even a quarter of his subscribers decided to pay a dollar a month, he'd be racking millions as soon as the next payment goes through (he has 9 million subscribers).
They all release their content for free, available for everybody; the Patreon rewards are what one might call "supplimentary material" and doesn't affect the overall YouTube content experience. If each of those popular YouTubers hid behind a paywall all of a sudden, their userbase would collapse. Like rd95 said: they're good, but not that good; well, maybe beside CGP Grey's. It would lead to other, less-known before-paywall YouTubers rising in popularity, however, so it's a sword with both sides sharp (what's the idiom for it?).