I don’t know why this didn’t occur to me sooner. Even if you just use a junk account to like and subscribe it’s the cheaper version of donating.
PBS Terra, for one, has actual climate change news and science. In addition to all the other cool things, and, ofc, PBS kids.
Here’s the list: NOVA PBS official, PBS, PBS Terra, American Experience PBS, Frontline PBS Official, PBS Documentaries, PBS NewsHour, PBS kids, PBS Eons, PBS Origins, PBS SpaceTime.
Each channel needs 1000? subscribers to monetize at all. And then there’s the algorithm. Searches often include items with more not less subscribers, and monetization flows from there.
Your subscribe feeds the channel into the algorithm.
500 for first level monetization like members and super chats/thanks/3rd thing
edit: 3rd thing = stickers