Sometimes you have a pet project that you intend to run on a real browser only (nowdays Safari lags behind even Edge, which makes me very sad), so you can drive in the fast lane. In the workplace? Of course we do webpack and the whole mumbo jumbo. Really, I love webpack, but on the main project our startup time is around 3-5min, hot rebuild time is 5-40sec and yes, we know what we are doing. Plus we do support IE10, we have dropped IE9 lately (and then it's not even a real corporate client, mind that).