User blog comment:Tedgill/Making Ads Better: How We're Going to Do It/@comment-5014364-20170201144129/@comment-20644-20170203224801

We want to make sure that videos are optimized so that if they do auto-play (without sound, since we don't allow auto-sound ads), they don't hurt page performance. Being able to remove programmatic ads from the page helps with that as well.