Bootstrap provides an easily customizable (through SASS/LESS variables) base for a web project and the components are very useful. You can even pick/choose comp

Bootstrap provides an easily customizable (through SASS/LESS variables) base for a web project and the components are very useful. You can even pick/choose components now to keep it more barebones if you wish. It's also very easy to learn. All the utility classes are useful too. Why waste time creating all those components manually? Also as you say it's still great for prototyping and internal applications that don't need bespoke styles.