If you're making educational content to be embedded into another site, you don't need YouTube. Because you are not using Google for video discovery. So put your video elsewhere. Vimeo, PeerTube, etc. Preferably multiple places.
Relying on Google to maintain a non ad supported product is very risky. Basing a business on it is suicidal. See the infamous list of dead Google services.[1]
Youtube allows unlimited videos with unlimited size and with good quality completely for free. You can also keep ads disabled if you want. No other service is even comparable.
I had thought that such ads only appeared when the video included content that belonged to another company that chose to puts ads on it, like if you made a music video but used a song owned by a record label. Do they put ads on stuff that's entirely yours? It's mentioned in their FAQ: https://support.google.com/youtube/answer/2475463
YouTube alternatives sound great until you actually try them.
The best exemple is when youtubers leave for reasons related to monetization. They always came back when they foud out that not only do other platform don't pay them (without a pay wall) but good platform will actually charge them for the hosting. finding your own ads is also really fucking hard when google isn't doing it for you.
Free unlimited 4k@60 video hosting is a hard to beat when users are extremely hostile to paying for thing they used to have for free (look at the feedback from. Youtube premium)
Relying on Google to maintain a non ad supported product is very risky. Basing a business on it is suicidal. See the infamous list of dead Google services.[1]
[1] https://killedbygoogle.com/