There’s plenty of speculation that YouTube has never turned a profit. We have no way to know for sure, though.
TikTok is quite different since it’s shorts only. I can totally see that being a viable model, because you can more comfortably cram ads between pieces of content. That’s why YouTube is pushing shorts so heavily.
Nebula is propped up by private investment. I had a quick look and found SEC filings which indicate they have raised over $9 million dollars in private investment in the past 3 years.
Patreon has almost no video hosting compared to how much revenue they have.
Out of curiosity, have you actually spoken to blind people about how useful they find Braille?