Good point, but, you can argue that ChromeOS isn't actually the OS in that case. Linux and HTML5 are. ChromeOS is more or less a detail of the hardware that mat

Good point, but, you can argue that ChromeOS isn't actually the OS in that case. Linux and HTML5 are. ChromeOS is more or less a detail of the hardware that matters to admins who want/need total control and entirely cattle-like devices (the unique value prop). I agree with you though that people are mostly writing to abstraction layers. That's where the action is, which is why it's curious that Fuschia's approach isn't clearly a ChromeOS style "portable abstraction layer + shell to invoke abstracted apps". They use Dart and Flutter for the UI so in some ways it is, but then they have the whole component model and Fuschia specific APIs.