I do agree alot with the article. One of the major use case SPAs was optimization hack that service worker can do easily. Service worker are like proxy middleware and are capable of some nifty tricks. Since I am not in web dev that much so I never actually managed to develop a project using it, but I felt that the templating could done fully in service worker. It will be faster as long the templating/transcompiling is not a bottleneck as the on wire format will be smaller. The main issue will be bootstrapping as you need to load a page first to install the service worker. I wonder if there is a good solution to that? (One idea is a service worker middleware on node so you can the service worker in the server side on first time use).