YouTube has already made it pretty risky for creators to stake their livelihood on advertisement money, as YouTube can decide to demonetize videos and channels pretty much arbitrarily with no quick recourse (which is important given how front-loaded video view rate is) if a recourse is available at all, and companies can steal a large chunk of advertising revenue even for content that should fall under fair use. On top of that, YouTube can also put ads on videos even if creators haven't set them up, in which case the money does not go to the creators.
As such it hasn't been worth it for creators to rely solely on advertising revenue or YouTube premium revenue for a while. YouTube, through its total disregard for creators, has long since made it not a stable source of income in the way that the others can be.
Given the value of the average ad impression, a micropayment system that charged cents to each user is all you need. The problem at the moment is that while advertising is "good enough" there's little market pressure for publishers/creators to align on a common micropayments system.
There is great content in YouTube for sure but let’s face it, 99% is garbage designed to 1) latch on to popular trends to get more views and 2) use that to show ads and generate revenue for what’s essentially no content at all - just random garbage.
The parent comment is basically pointing out that you're depriving the creators you watch of ad revenue. If you sponsor the creators you watch directly, that's great! But most people don't, and even for the people on HN I suspect that they watch a lot more different channels than just the ones they sponsor.