When it comes to better user experience and robust websites, we'll always be reminded that tools & techs given or much supported by google are so many, like SPDY (now HTTP/2) , PageSpeed Server Modules, WebP, WOFF2, WebM, Quic (experimental)
In Many google always implemented many new things or provide lot of support and helper resources for these new things to be quickly adopted by community and chrome is always ahead in race to support all at its best.
WorkBox is kind of more general solution for everything after sw-precache and sw-toolbox libraries
WorkBox is also yet another google's js open source library to ease the task of cache assets and take full advantage of features used to build Progressive Web Apps.
Key WorkBox Features
Flexible Routing Pattern
Regex based routing to support routing patterns of asset urls in many features, its more easy and much flexible.
Caching Strategies & Background sync
With inbuilt many type of Caching Strategies we've full control over how assets are cached, served, re-validated and updated on every request, and it manage the background sync as well with giving full control over it. even using routing we can alter the caches on runtime and pre-cache certain things or app as whole.
Storage Quota Management
if we going to cache a lot unnecessary stuff, that may leads to troubles for further storage, thus WorkBox comes up with expiration and other goodies to have best practices without getting over quota.
tight integration with server side make our app more easy to mange and many task be automated like pre-caching of resources to allow browser to fully download app so it can available when offline. it has hooks for gulp, webpack and can directly used over CLI or from node-js well.