I had this idea ~2002 and I told this to a group (herd?) of MSFT engineers at a conference. They asked me a lot of questions and seemed excited. The next time I thought of it was when I heard of Citrix which I believe had a product which allowed you to stream any application on any device. Then, I heard Frame (or was it Frame2? Or was it called Terminal? Anyway, some company named like that) did this. And most recently, a startup called Mighty (now pivoted?) tried to do something similar but for performance reasons. It's not a bad idea and is probably the inevitable future of a "consumer" cloud. Security is just one benefit, I believe the thin client architecture has a host of other benefits.