I used Brilliant (https://brilliant.org/) with my kids and it was helpful, if only because they did try to explain some of the theory around the work in different ways. Considering your comment around videos and artwork, it might not be what you are after, but you can check out some of their free courses to get an idea of how they work.

The biggest issue for me was that it is concept based rather than curriculum based, so it wasn't perfect for trying to teach them on a regular basis, but it was helpful if we encountered a topic they didn't understand.