Maybe my users want to do more things with their computer than just display a website. And maybe they don't want my website to prevent their processor from entering a sleep state because it does unnecessary background work. Maybe my users pay for their data, or maybe they have a poor connection.

> And maybe they don't want my website to prevent their processor from entering a sleep state because it does unnecessary background work.

Good news is that a service worker can't do that. It gets automatically shut down after a short period of time. It will be woken up again in response to push notifications, which you must request permission for, or in response to a new user event.

> Maybe my users pay for their data, or maybe they have a poor connection.

Which is why providing greater offline capability is a good thing, not a bad thing.