Because you all stopped to use serverside rendering and let the browser do risky stuff. If you want to cut down the overhead, use a simple PHP app and deliver

Because you all stopped to use serverside rendering and let the browser do risky stuff. If you want to cut down the overhead, use a simple PHP app and deliver prerendered HTML with JS just for the ajax calls. Its fast, reliable and tested in the wild. Servers are so powerful they can handle thousands of users at the same time. You also don't drain the users batteries anymore, a win-win.