Add in Favourite and Multiple Character uploading and switching betwen my uploaded characters option must be available in Mixamo. And one more thing, Upload custom animations from users to share with community option will make the Mixamo most useful. Please do something to get these options.
Animation page loads animations which makes it slower, Gif pics may be used by Mixamo in animation list, which will make website faster.
Mixamo is dead software Adobe just keeps online because it doesn't cost them so nothing is going to be fixed or added