[codepo8-hn]

1) The idea of the web is that the boundary between consumer and creator is very blurred. It is a world-wide, distributed environment. Making the tool you consume also the tool to create empowers a lot of people. Consider yourself a budding publisher on a very bad connection in an emerging country: you download a browser to surf the web, and that one now also enables you to create something for it. Downloading xCode or Android Studio would take ages. For developers, this is also an advantage: you use the same browser your end users have. In the past developer add-ons interfered with the rendering of the page and the performance of the browser. This gave you false results. 2) Whilst devtools make any browser bigger in initial file size (including Chrome and IE), it is not a large part of the main download (fonts are actually a huge one). The performance hit is to the overall computation (much like a standalone tool would) but isn't impeding on the browser performance itself.