It was probably fun to make, but there are so many issues (nat, bandwidth costs for users, browsers not processing background pages' tasks well, etc) that I can't see actually using this in any real-life scenario.
And also I agree that there were a lot of problems to work around and benefits are not that obvious if application size is 3 Mb. However it becomes closer to real life with every additional megabyte of application size. E.g. for video content it definitely worth and it also could work for web games and VR experiences. Other cases? Sure there are some. Let`s consider this as first Viral JavaScript implementation.
And also I agree that there were a lot of problems to work around and benefits are not that obvious if application size is 3 Mb. However it becomes closer to real life with every additional megabyte of application size. E.g. for video content it definitely worth and it also could work for web games and VR experiences. Other cases? Sure there are some. Let`s consider this as first Viral JavaScript implementation.