There are many factors that contribute to a slow website. Some are technical, like hosting, the theme you use, the number of plugins you use. Some of these are choices, such as Image Size, Streaming Video, Ads and Social Feeds. Big images, Video, Ads and Social Feeds slow down a website but increase conversion. Faster is always better, but before you make a decision, there is a balance to be had, and OFTEN companies choose conversion (selling products) over load speed.