I am surprised by the fact that author completely ignores client side caching using browser and service worker, as well as SSR. One key point of PWA is that it

I am surprised by the fact that author completely ignores client side caching using browser and service worker, as well as SSR. One key point of PWA is that it works offline and loads faster after after first load (even after you deploy new changes, with basic service worker configs from sw-precache). So you need 1 second for first load only. Subsequent loads are much faster.