Yeah, the budget for any major cosmere adaptation would have to be enormous, but animated would be considerably cheaper.
What style of animation do you think would work best (or look coolest)? A lot of recent-ish animated films/shows have broken a lot of the standards, like Arcane and Into the Spiderverse. There is, of course, the traditional Disney-style 3D animation, or a more traditional 2D animation. Personally, I would like to see more unique types of animation for a cosmere adaptation. I think it would complement the unique magic systems and add more character. Live-action feels more realistic and grounded, but since this is high fantasy, I think a less realistic and more fantastical adaptation would work better.