Is Chrome OS of today anything more than a locked-down version of Windows? [COMPACTIDEA]

Ever since I started using Google's Chrome OS on a Asus Chromebit a few weeks ago, I've felt that maybe Chrome OS is nothing more than a highly locked-down version of Windows. Windows can be stripped and locked down so that it'll run nothing but a Web browser. It could be packaged on a USB stick and optimized in a way that booting [and shutting down] would take place in seconds. Other customizations could be made easily as well. What makes Chrome OS different/novel, if anything? Isn't Chrome OS a subset of Windows? Isn't it an OS that can run only one application - the browser? Can't Windows be "reduced" to start mimicking Chrome OS and thus start providing the admittedly many genuine benefits of Chrome OS? It looks very much possible, especially since Google itself constructed Chrome OS by initially starting with Linux. The many shortcomings of Chrome OS could be addressed this way [for example, not having a lightening-fast Notepad to quickly write down something].