From what I hear from my colleagues from VFX, doing things with Unreal is becoming quite a thing.
Animation would be great, but selling that to mainstream audience is a lot harder than live action show with CGI.
Good animation show is likely to be much more successful and less expensive to break even. A crap TV show is likely to generate nothing but bad press and pass mostly unnoticed
There is market for animation, even if it's smaller than live actions. Arcane made far more buzz than The Wheel of time.
It's not like Cosmere had such a high marketability potential anyways. A live action seems like just a huge waste of money