At the end you pointed out the issue : the browser is good at displaying documents, but a program wants to run in the OS directly, and trying to make the browse

At the end you pointed out the issue : the browser is good at displaying documents, but a program wants to run in the OS directly, and trying to make the browser an OS inside the OS only makes sense if you are Google and are trying to wrestle with Microsoft for the control of the OS that the average user is exposed to.