Every website has different business requirements. Some are built for speed, while others are built for stability. Some are built to balance speed and stability. Admittedly, all websites have to deliver the data they are supposed to deliver quickly and accurately to those that are supposed to receive it.
Many people do not realize that Google penalizes pages that take longer than 6 seconds to load. If Google penalizes you, this means you are going to be substantially less-likely to come up on Google search, thus sending potential customers directly to your competitors.