In my experience (long years as consultant/admin in the MSP business), it's always the database server or the network that is too slow, and it's never the SQL query or missing indexes. Cough magento cough </s>
According to popular HN opinion, nobody runs servers anymore. Hipster coders leveraging AWS techno BS are never going to realize they are absolutely clueless and burning money by the ton.
Same as in the gaming industry. Why bother starting from scratch. We want MVP right NOW, so just slap a bunch of random libraries together. People are going to buy faster GPUs anyway, right, and we'll fix issues later.