Using Service worker is a good way to make your website offline but there are many problems.
Using service-workers for normal sites for caching when you have no intention of making site offline ... DON't USE. Browser caching with headers work way more simpler & in a controlled manner than service-workers.
Identifying the right caching policy for service-workers is always a headache. Most of the time it will keep old cache (everything) no matter your content on server is updated or not. ( As it doesn't check for caching headers or E-Tag policies).
There are lot of more issues you will encounter when you start using it.
So, if you have plans to make your website offline go for it.. Otherwise don't go if you are planning to use it for normal caching n stuff and don't have enough time for proper research.