No. I'm in favor of features that enable new uses cases, either by providing a new API (e.g. WebBluetooth) or by massively increasing performance (e.g. WebGL,

No. I'm in favor of features that enable new uses cases, either by providing a new API (e.g. WebBluetooth) or by massively increasing performance (e.g. WebGL, WebAssembly). Features that can be built on top of those foundations should not be shipped in browsers for the reasons that I mentioned before.