We all remember the ways when flash-based animations ruled the web and the best websites had the highest number of visitors. This world came to a sudden halt when the mobile era started and mobile phones provided no flash compatibility features. This basically took flash from the top of the food chain in web design, to a completely obsolete status.
There are now other programing methods to implement flash on websites, but the truth is that we are living in an era that rewards simplicity and fast loading sites. Animations are only going to get in the way of that minimalistic and simplistic approach and that is going to force you to waste time trying to optimize loading times. The point is that animations should only be used when extremely necessary and the use of streamed video is more than enough to solve the problem.