Which is still an unstable draft, so I don't see the point in using it today. Service workers are nice but nothing earth-shattering, there are more interesting

Which is still an unstable draft, so I don't see the point in using it today. Service workers are nice but nothing earth-shattering, there are more interesting features in development at the moment: https://webkit.org/status https://webkit.org/status. According to the list they are also considering implementing service workers so it is not all drama.